Serfas TailbonesA(R) saddles supports the sit bones and provides a smooth comfortable ride using Progressive Density Foam while a Deep Groove Design allows maximum blood flow into the neurovascular bundle for drastically reduced numbness and discomfort.Our latest addition to the TailbonesA(R) family introduces a top layer of Memory Foam for a more personalized feel as well as added comfort. Lycra Cover Specs: Length: 267mm / 10.5" Width: 185mm / 7.2" Weight: 638g+/- Vinyl Cover Specs: Length: 259mm / 10.23" Width: 190mm / 7.48" Weight: 566g+/- Features: Elastomer Suspension Top Layer of Memory Foam For Added Comfort High Sit Area For Soft Tissue Relief Progressive Foam Technology Deep Groove Design with Cut Out Relaxed Riding Position Rails: Steel Cover: Four-Way Stretch LycraA(R) or Waterproof Vinyl