Patented Body Geometry design is lab-tested to assure blood flow to sensitive arteries. Elaston foam provides unrivaled comfort and support on longer rides. Low-friction panels on the nose and tail improve pedaling efficiency and mobility while moving on and off the saddle. Ultra-light, strong, and oversized FACT carbon rails. Level II padding: Medium density foam for bike feel with additional cushioning. Size 143mm / Weight 207g. Size 155mm / Weight 219g. NOTE: Oversized 7x9mm carbon rails are not compatible with seatposts equipped with side-load clamp mechanisms for 7mm round rails.