I purchased a size M-L, but it doesn't fit, so I'm selling it. I wore it over an undershirt about twice, for a few hours each time, but it was too small for me. It's used, but I've only tried it a few times, and it's relatively clean. I hope someone can use it. Please understand that it has been stored at home. I would appreciate it if you could purchase it. There is no box or instruction manual.