Patented Body Geometry design is lab-tested to assure blood flow to sensitive arteries. Super-light padding for comfort and performance on longer rides. Stiff, carbon-reinforced shell with flexible Adaptive Edge technology. Ultra-light and strong, oversized FACT carbon rails are smoothly integrated into the base. Tough, lightweight, and water-resistant Micromatrix™ cover. Level 2 padding: Medium density foam for bike feel with additional cushioning. Size 143mm / Weight 159g. Size 155mm / Weight 165g. NOTE: Oversized 7x9mm carbon rails are not compatible with seatposts equipped with side-load clamp mechanisms for 7mm round rails.