G-Form Pro-X3 Knee Guard - Street Art 2X-LargeG Form Pro X3 Knee Guard Street Art 2X Large. The G Form Pro X3 Knee Guards provide comfortable and lightweight protection. Designed for trail all mountain and cross country riding these knee guards feature G Forms SmartFlex pad technology. SmartFlex pads offer form fitting and lightweight protection that is flexible as you ride and hardens on impact Body mapped impact absorbing SmartFlex pads layered on top of a ventilated soft inner foam layer