I have size large ftw. I really like them. Thick foam for protection, but still flexible, and I really like how they are vented too. But, I find the large size a little oversized. But, I am okay with it. Different size options are a plus. Granted, for most adult size player I would recommend medium. Smalls are for skilled positions that want to get busted kneecaps but still be allowed to play or youth players. Large for larger guys (linemen) or pants that have the pockets for large pads.