Although this is a very expensive jersey, if you have high demands and want a jersey that: fits right like a proper MTB jersey, is very very lightweight, and you typically only tend to like the best, this is the jersey for you. For sizing reference, I am 5'10" and 170 lbs and the large fits well. I like to have a little movement and flow in the jersey, not for it to be tight, especially in the arm pit area, like a road jersey, and for my height and weight Large fits like I think a MTB jersey should. Despite being very light weight, this jersey is tough. Only my second ride wearing it, I crashed over a big drop, resulting in a crash that severely sprained the rotator cuff in my left shoulder, such that still 6 weeks later now I still cannot even get back on the MTB, the jersey on that shoulder where I crashed not even scuffed!!! My elbow had a huge, deep scrape despite wearing POC elbow pads too, so at least for the type of crash I had, on dirt, the jersey held up well. Can't wait to heal up and get back on my bike in this awesome jersey!