Fly Racing's HDM (High Density Memory) protectors are made of a special blend viscoelastic foam with memory function allowing for repeat impacts The pads are both soft, lightweight and low profile to ensure they stay comfortable even on long days pedaling in the saddle The protective pads feature an array of breathe holes to help flow cooler air into and through the pads 4 way stretch mesh panels at the rear help in giving a great fit and allowing hot air to escape keeping the pad feeling cooler Extended upper cuffs help to try and stop the pads slipping down during use