Formula 420 Universal Caps for Cleaning, Storage, and Odor Proofing

These stoppers work well and help you clean things much more efficiently. They’re the best product I’ve found for the price.

These things are great! No more plugging holes with your thumb in order to shake around your cleaning solution!

They came on time. The only thing is that they could be a little bit bigger and wish they would stick on the glass a little bit better then they do cause they keep falling off and won't stay on very well.

These make cleaning your device a breeze and they help save you on rubbing alcohol. They can get very slippery when wet, so be careful to put them on dry. I recommend them to anyone who likes to keep their administration devices clean on a regular basis.

The large cap failed immediately upon first use. It went on fine but a hole appeared as soon as I started shaking the glass. The small cap worked great. Stayed on and did not fail. It's a great idea but they just need to make the rubber more durable especially because the caps are exposed to chemicals. I used the All Natural by Formula 420 glass cleaner. Wish I would have used this before the return window closed!

Holds on decently. It can come off but just don’t go crazy with it. Otherwise it fits great. Kind of a condom feel

This product is fantastic at cleaning glassware but be very careful using it. I was super excited to try this product. As soon as it came in I filled the trusty glass “vase” with alcohol, popped the caps on, and shook the hell out of the “vase” like it was a shakeweight in 2009. At first everything was going great and the caps felt secure until they weren’t anymore, my living room would soon be covered in isopropyl alcohol and my own vomit. As I was shaking the “vase” the larger mouthpiece cap slipped off, sending alcohol flying directly into my face, mouth, and eyes, and all over my partner, dog, and living room. I then began to throw up profusely all over my living room due to the isopropyl alcohol in my mouth and nose. Just as I thought this situation couldn’t get any worse, I slipped on the alcohol/vomit combo that was now covering my living room floor and pulled a muscle in my back. The product works fine but due to the aftermath I would give it 3 stars.

Easy to use, and work pretty well. They will discolor, but doesn't affect the performance, so far.

Product works absolutely perfect. I put the small one on the down-stem hole then I fill my piece to the brim with Zep before placing the top cap on. I’ve never had a leak even with that much liquid and I use them almost daily. A tip for future users, make sure you dry off the inside of the cap as well as the mating surface on your piece before use, moisture after applying is obviously fine cause it won’t leak at all.

Good just don't use with Randy's black label it will eat right though them

I use 99% iso to clean my glass and these caps stood up to it and didn’t ‘disintegrate’ during cleaning. Unfortunately they didn’t last very long, maybe a month or so before they started getting micro tears, likely from my nails but possibly from wear. I really like them for storage, as it keeps the smells inside. I may give them another try and treat them more carefully next time to see if they last longer.

I had great hopes for these, they fit my units. However when I went to use them for the first time in combination with the 420 cleaner they ripped right in front of my eyes! As I tried them on before cleaning I know they didn’t tear because they didn’t fit. But the cleaner actually caused them to disintegrate and rip. Great idea but need to be more durable.

The idea behind the product is solid and would obviously do the job. I received mine the other day and proceeded to try out the larger of the caps to give my bong a clean.. The cap worked great for the first 5-6 shakes of the cleaning until it popped a hole right in the middle of it out of nowhere. I am not sure if the material was not quite up to par as I was using the larger cap, didn’t poke it with anything, and didn’t have it stretched to any crazy length, for a stretchy product it was conservatively applied. Still just pop, a hole appeared, covering me with a small amount of the wonderful “juices” that had been flowing around. If you get a product that happens to not spring a leak, they are a must have took for sure. Wouldn’t want to clean without a cap and plugs again after trying them for the first time. Having used my hands and fingers my whole life and always getting those few drops trickling down the arm even when trying quite hard to prevent it, these opened my eyes to a new world of possibility. May try and order again, or at least something similar if necessary.