Let me tell you about this chest protector. I went back and fourth for awhile on whether or not I needed this much protection. Well, I'm very glad I did. I went on a mountain biking trip this past weekend and took 3 nasty spills. I got up like nothing happened.This thing just ate up the rocks. Saved me one time from OTB crash and landing on a sharp rocks. Second time I got into some loose gravel and slid out and my elbow went into the rock. Not a scratch on it. Truly amazed at how well this protected me.Sizing:Some reviews say that it is not true to size. I can tell you it fit me very well at 5'10, 175lbs. I went with Large size. Very easy to zip, just don't zip your skin. I wore nothing underneath a jersey on top.If you want good protection, I highly reccomend this. Especially, if you plan on eating some dirt on some wild trails and jumps.Just send it!