Features Designed Specifically for Roller Derby. Low profile and less bulk with high level protection. 187 Killer Pads Lock-In Core System. Removable foam allows for easy washing, Interlocking straps link foam to center of pad casing. V-22 Dual Density Foam. Specially formulated to provide the perfect combination of cushion and protection for multiple hard impacts. Rapid F L E X Hinge. Allows pad to respond freely to full range of motion; straighten or bend leg with little or no resistance. Fusion Groove Channel. Maintains foam connection to skaters leg and helps eliminate pad slip downs. 187 Killer Pads Lock-In Cap System. Secures and aligns removable cap in correct position More Features Light-weight fast drying interior lining Seamless interior finish for ultimate comfort Ballistic nylon with industrial-weight stitching ensures durability Three-panel construction for reliable performance Open back design for excellent fit and quick on off The Pro Derby Knee Pad brings years of roller derby experience from the rink to your knee. Through the input of top skaters, product features have been tested and perfected. Experience the difference.