TSLAMen's Thermal Underwear Set, Microfiber Soft Fleece Lined Long Johns, Winter Warm Base Layer Top & Bottom

Q: What size do i buy? Im 5'-9, 185, 32"waist, and typically wear medium bottoms and large tops.

I'm 180cm (5'11), 75kg (170lbs) and ordered size medium. They were a good fit. The fit isn't supposed to be loose as it otherwise defeats the purpose.

Q: What size do you recommend for a guy whose 6’2 190lbs?

This item runs small. My bf is an XL and he barely fit in that size

Q: What is the mhs100 and mhs103? Apparently you can order it either way and I don't know what it means or what the difference is.

According to the description the 103 has the fly front for easier access for the bathroom, the 100 does not. I do not see anything that says it refers to material density.

Q: what size would you suggest for 6'1" and 125 lbs, 29 waist? can't decide between small or medium. any suggestions?

I purchased this for my roommate he's six foot four and between 190 and 200 lb I bought him a large and it has fit him excellent. He's very happy with The Thermals he just thanked me again the other day and said they work great. Lot of give and flex though they fit close to the skin. I would give it a 5-star rating based on his reaction and comments. Thank you hope this helps