Fox Racing Launch Pro MTB Knee Guard Silicone gripper behind the knee to keep the pad in place Perforated neoprene for breathability Pre-curved ergonomic fit Elastic strapping top and bottom to keep the pad in place Available in sizes Small/Medium, which fits thighs between 14.5" - 16" and calves 13.5" - 15", and Large/X-Large, which fits thighs between 16" - 17.5" and calves 15" - 16.5".