KOCLESMen's Body Shaper Compression Cooling T Shirt Shapewear Undershirt

Q: I am 5’5 155 what size

For me I am 5'6 at 160. I wear a Medium and fits perfectly. If you cant find a good answer, a Medium may be the right size for you. So that will be US size Medium with a tag size Large as they mention in the size drop down list they have.

Q: Am 5'8 weight 220 lbs , should I get an extra large size?

This is NOT the US size, get one or two sizes larger, I'm the same heigh and weight. If you want more compression，then get one size bigger XXL, for hiding the "man boobs" and the "beer belly", this shirt really helps, but you need some time to get used to it, when you first try. As for size 3XL , I think it is an ideal undershirt, just fit well and comfortable.