Engineered for off-road riders, the Bionic Flex Knee Protectors are Alpinestars MX knee protectors delivering flexible, ventilated impact protection for motocross. Featuring highly perforated Nucleon Flex Technology protectors externally on a breathable stretch-mesh sleeve, they are CE-certified to EN 1621-1:2012 Level 1, with an elasticated top strap and silicone hems for secure positioning, improved ventilation, and unrestricted movement, plus an abrasion-resistant front panel and side foam padding.