The Alpinestars Bionic 5S Youth Knee Guards (sold as a pair) offer innovative hybrid frames constructed from a rigid composite over-injected with a high-performance fibre-reinforced polymer, which provides optimal structural integrity and support while being ultra-lightweight and adaptive. The slim ergonomic design provides riding comfort during dynamic movement. The highly stable, slim-design four-point hinge system perfectly follows the articulation of the knee. It incorporates easily exchangeable extension stops (0, 10, & 20 degrees), which reduce the risk of sustaining injuries to the medial and lateral collateral ligament, the anterior and posterior cruciate ligament and the lateral and medial meniscus. The lightweight and highly ventilated knee-cup system offers strong impact force dispersion and absorption while ensuring maximum coverage area in all riding positions. CE EN 1621-1:2012 Level 1 and UKCA certified.