--- product_id: 272328882 title: "LCD Display, Electric Voltage Tester" brand: "klein tools" price: "€ 36.00" currency: EUR in_stock: true reviews_count: 13 category: "Klein Tools" url: https://www.desertcart.de/products/272328882-lcd-display-electric-voltage-tester store_origin: DE region: Germany --- # Detects wiring faults Clear LCD readout Precise GFCI trip time LCD Display, Electric Voltage Tester **Brand:** klein tools **Price:** € 36.00 **Availability:** ✅ In Stock ## Summary > ⚡ Power up your safety game with precision testing! ## Quick Answers - **What is this?** LCD Display, Electric Voltage Tester by klein tools - **How much does it cost?** € 36.00 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.de](https://www.desertcart.de/products/272328882-lcd-display-electric-voltage-tester) ## Best For - klein tools enthusiasts ## Why This Product - Trusted klein tools brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Built to Outperform:** Durable, professional-grade design trusted by electricians for over 160 years. - • **Hands-Free Convenience:** Auto-Hold locks readings for those hard-to-reach outlets—effortless testing every time. - • **Pro-Level GFCI Testing:** Trip time display lets you troubleshoot GFCI devices with pinpoint accuracy. - • **Instant Voltage Clarity:** Large backlit LCD ensures no guesswork—read voltage and wiring status at a glance. - • **Next-Gen Fault Detection:** Patent-pending tech spots open neutral & ground faults others miss—safety first. ## Overview The Klein Tools RT250 is a professional-grade GFCI outlet tester featuring a large backlit LCD that displays voltage, wiring faults, and GFCI trip times. Designed for standard 3-wire 120V outlets, it includes innovative open neutral and ground fault detection, an auto-hold function for convenience, and comes with batteries included. Trusted by pros and DIYers alike, it delivers fast, accurate, and easy-to-read diagnostics to ensure electrical safety and compliance. ## Description The RT250 is an electrical receptacle tester that tests the wiring conditions at an electrical outlet and inspects GFCI devices. The LCD displays the voltage, identifies the wiring fault, and the time required to trip a GFCI device. It is designated for use with North American 3-wire 120V electrical outlets. For more than 160 years, Klein Tools has manufactured premium-quality, professional-grade hand tools that deliver the performance, durability and precision needed to get the job done right. Our family of engineers, workers and craftsman continue to put six generations of expertise into every tool we create by using only the highest quality materials, superior workmanship, and keeping manufacturing as close to home as we can. Klein isn't just the name of our company, it's also our family name. And since we're an American company that's family-owned and family-run, you know you can count on us to be here tomorrow. Klein Tools doesn't just make great products, we make great products that stand up to the demands of the professionals who use them every day ... Since 1857. Review: Simple and easy to use yet Amazing precision!!! - I picked up the Klein Tools RT250 GFCI Outlet Tester to help check a few outlets around my house, and I’m honestly impressed. This thing is super straightforward, just plug it in, the lights pop on, and you instantly know what’s going on with the wiring. No guesswork, no complicated setup, just clear results. The display is bright and easy to read, and the built-in GFCI test button is a lifesaver when checking bathroom and kitchen outlets. It helped me identify a miswired outlet in an older part of my house that I never would’ve caught otherwise. For something at this price, it feels durable and professional like something an electrician would actually use. If you’re a homeowner, DIYer, or just want peace of mind about the electrical safety in your place, this is a solid buy. Fast, accurate, and super easy to use. Highly recommend! Review: A little more expensive than the simple testers but worth it - I have one of those 3 LED testers already, the ones with the 2 yellow and one red light... and has a legend on it so that you can tell what is what. Works great... only issue is that when I was working outdoors or in a brightly lit room, it wasn't so obvious which LED were lit. So I bought the Klein as it wasn't a bad price and had the built in GFCI too. My old set, I had a separate GFCI tester which also worked great but just meant I had 2 separate testers. I played with the Klein soon as I got it having installed the batteries (Klein supplied I might add!!!!). You need to hold the power button down a couple of seconds and then the LCD comes alive. I tried it in various outlets around the house and found it to be a really effective device. The unit has only 2 LED's and there's no mistaking when they light up, both bright... A green one which clearly means OK and a red one meaning a fault in the wiring has been detected. I already had a purpose made miswired test lead I used for verifying the fault detection capability. Works great. I also like that it provides a reading of the actual voltage detected. It's not just a passive device. I have only one minor concern... When I put this in my toolbox I'm worried about something resting on the power switch and running the batteries down, so for now, having already carefully cut around the edge of the packaging, I'm keeping it in the packaged plastic. Might be overkill and maybe I'll buy a protective case for it if I feel inclined but for now, perfectly happy with the device and definitely recommend over the typical passive receptacle testers, even though they may be half the price. ## Features - CLEAR LCD READOUT: GFCI Receptacle Tester features a large backlit LCD readout for easy voltage reading and clear indication of wiring conditions - TRIP TIME DISPLAY: LCD readout shows the time required to trip a GFCI device, allowing for quick and accurate troubleshooting - DETECT COMMON WIRING FAULTS: Detect and identify common wiring faults, ensuring electrical safety and proper functionality of GFCI receptacles - PATENT-PENDING OPEN NEUTRAL & OPEN GROUND DETECTION: Innovative detection system identifies Open Neutral and Open Ground wiring faults, enhancing safety measures - CONVENIENT AUTO-HOLD FEATURE: Auto-Hold function holds the reading for hard-to-reach outlets, providing convenience and ease of use ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B08QW7K1JJ | | Best Sellers Rank | #698 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #1 in Voltage Testers | | Brand | KLEIN TOOLS | | Brand Name | KLEIN TOOLS | | Color | Multi | | Customer Reviews | 4.8 out of 5 stars 11,461 Reviews | | Global Trade Identification Number | 00092644693212 | | Included Components | 2 x 1.5V AAA Alkaline Batteries and Manual | | Item Dimensions | 4.53 x 1.16 x 2 inches | | Item Type Name | Klein Tools RT250 GFCI Receptacle Tester with LCD Display, for Standard 3-Wire 120V Electrical Outlets | | Item Weight | 4.16 ounces | | Item dimensions L x W x H | 4.53 x 1.16 x 2 inches | | Manufacturer | Klein Tools | | Maximum Operating Voltage | 120 volts | | Measurement Type | Voltmeter | | Minimum Operating Voltage | 120 volts_of_alternating_current | | Model | RT250 | | Number of Items | 1 | | Part Number | RT250 | | Power Source | Corded Electric | | Specification Met | CSA | | Style | Receptacle Tester | | Style Name | Receptacle Tester | | UPC | 092644693212 | | Unit Count | 1 Count | | Upper Temperature Rating | 60 °C | | Warranty Description | See Manufacturer Website | ## Product Details - **Brand:** KLEIN TOOLS - **Color:** Multi - **Item Weight:** 4.16 ounces - **Power Source:** Corded Electric - **Style:** Receptacle Tester ## Images ![LCD Display, Electric Voltage Tester - Image 1](https://m.media-amazon.com/images/I/61HibJa1brL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: Is it ok to use this tester for the 20a power outlet (not gfci)?** A: A Very good question, since the device name starts with GFCI. Answer is YES, because despite the name, the device is mainly a regular outlet tester, checking cross wiring, missing wiring, and reporting voltages, all worthwhile tests for non-GFCI outlet. Also works with 15amp & 30amp with adapter. Thanks for the question. **Q: Most of the outlets in the basement where i'm living say >6.00 when i test them. are they wired wrong? is it safe to use the outlets?** A: It is not safe to use those outlets. If an outlet is good, the green light on the tester should illuminate, and the display should register a voltage close to 120 volts. **Q: Is this accurate enough to measure with some confidence which is the most upstream receptacle in a circuit for choosing gfci location?** A: Resolution accuracy inadequate for that task. Displayed digits determines resolution. In this case, meter accuracy will not be and can not be better than +/- 1 volt because digital resolution is always +/- 1 in the least significant digit. Example: If measuring a true, standardised 120 volts, meter might display 119V (-1), 120V or 121V (+1) if calibrated/adjusted correctly. You've got the right idea, but this meter displays only 2-1/2 digits (120V). You will need a meter with 3-1/2 (120.0V) digits displayed. Worst case resolution at 120 volts will then be ~0.1V (100 mV). You need to see those millivolts differences. Get one with stated accuracy and preferably calibrated. Cheers! **Q: What will happen if you press the gfci test on a non gfci? will it do nothing. or will it trip the breaker in the panel, and i have to flip the switch** A: The amber lights on the tester will blink, nothing will trip. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Simple and easy to use yet Amazing precision!!! *by D***N on December 31, 2025* I picked up the Klein Tools RT250 GFCI Outlet Tester to help check a few outlets around my house, and I’m honestly impressed. This thing is super straightforward, just plug it in, the lights pop on, and you instantly know what’s going on with the wiring. No guesswork, no complicated setup, just clear results. The display is bright and easy to read, and the built-in GFCI test button is a lifesaver when checking bathroom and kitchen outlets. It helped me identify a miswired outlet in an older part of my house that I never would’ve caught otherwise. For something at this price, it feels durable and professional like something an electrician would actually use. If you’re a homeowner, DIYer, or just want peace of mind about the electrical safety in your place, this is a solid buy. Fast, accurate, and super easy to use. Highly recommend! ### ⭐⭐⭐⭐⭐ A little more expensive than the simple testers but worth it *by S***N on June 16, 2025* I have one of those 3 LED testers already, the ones with the 2 yellow and one red light... and has a legend on it so that you can tell what is what. Works great... only issue is that when I was working outdoors or in a brightly lit room, it wasn't so obvious which LED were lit. So I bought the Klein as it wasn't a bad price and had the built in GFCI too. My old set, I had a separate GFCI tester which also worked great but just meant I had 2 separate testers. I played with the Klein soon as I got it having installed the batteries (Klein supplied I might add!!!!). You need to hold the power button down a couple of seconds and then the LCD comes alive. I tried it in various outlets around the house and found it to be a really effective device. The unit has only 2 LED's and there's no mistaking when they light up, both bright... A green one which clearly means OK and a red one meaning a fault in the wiring has been detected. I already had a purpose made miswired test lead I used for verifying the fault detection capability. Works great. I also like that it provides a reading of the actual voltage detected. It's not just a passive device. I have only one minor concern... When I put this in my toolbox I'm worried about something resting on the power switch and running the batteries down, so for now, having already carefully cut around the edge of the packaging, I'm keeping it in the packaged plastic. Might be overkill and maybe I'll buy a protective case for it if I feel inclined but for now, perfectly happy with the device and definitely recommend over the typical passive receptacle testers, even though they may be half the price. ### ⭐⭐⭐⭐⭐ Clear, accurate, and incredibly helpful *by B***K on March 10, 2026* This Klein Tools RT250 Outlet Tester is a significant step up from the basic three-light testers. The LCD display is bright and easy to read, giving you actual voltage numbers and clear text for any wiring faults. It takes all the guesswork out of troubleshooting, and the GFCI trip testing function works perfectly every time. It’s a rugged, well-built tool that feels like it will last for years. Highly recommend it for both professionals and home DIYers! ## Frequently Bought Together - Klein Tools RT250 GFCI Outlet Tester with LCD Display, Electric Voltage Tester for Standard 3-Wire 120V Electrical Receptacles - Klein Tools 80016 Circuit Breaker Finder Tool Kit with Accessories, 2-Piece Set, Includes Cat. No. ET310 and Cat. No. 69411 - Klein Tools NCVT3P Dual Range Non Contact Voltage Tester, 12 - 1000V AC Pen, Flashlight, Audible and Flashing LED Alarms, Pocket Clip --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.de/products/272328882-lcd-display-electric-voltage-tester](https://www.desertcart.de/products/272328882-lcd-display-electric-voltage-tester) --- *Product available on Desertcart Germany* *Store origin: DE* *Last updated: 2026-09-14*