Fizik Vento Antares R1 - 150mmFeatures Low profile performance design for optimal pedaling efficiency and power transfer Ride compliant, carbon reinforced nylon shell and stiff carbon rails for lightweight stiffness Double density foam, firmer on ischial bones and softer on the nose for optimal comfort Dimensions: 268 x 140 150mm with synthetic cover and carbon shell Carbon 7x9mm rails for added durability and support