Youth K4 2.0 Knee Braces - Danger Boy V2 LE. POD's new patented and medically certified K4 Knee Braces offer an affordable alternative to knee guards and are clinically proven to reduce the prevalence and severity of knee injuries. Impact Modified Frame: Impact Modified Lightweight Composite frames anchor to the hinges for optimal load transfer away from the knee joint, without compromising feel for the bike. The patented technology is proven to reduce the risk of knee injuries while delivering unprecedented levels of strength, comfort, reliability and performance. POD is so confident in the strength and protection of the Impact Modified Composite K4 frames that they back it up with a two year warranty. New Human Motion® Hinge: