Alpinestars Men's SX-1 Knee Guard (White/Black, Small/Medium) Upper and lower frames are constructed from a high performance polymeric material blend foroptimized levels of flexibility and strength as well as excellent weight saving properties Polymer protector plates are strategically perforated for maximum breathability and air ventilation CE certified knee brace to the latest EN 1621_1: 2012 K type A (Level1) Upper frame features extended frame for increased thigh protection without compromising mobility Innovative patella construction features 'floating' protection cup for continuous coverage and mobility regardless of leg position