Fizik antares r1 open road bike saddlewith its neutral shape and pressure relieving cut out, the antares r1 open model is an ideal road bike saddle choice for endurance cyclists. Lightweight, supportive and with a slight amount of flexibility in its shell, it helps you to easily find your ideal riding position for optimum power output.a saddle for medium flexibilitythis saddle is ideal for riders with a medium amount of spine flexibility and those who have a minimal amount of pelvis rotation when pedalling.advanced shell designthe shell is a carbon fibre reinforced nylon, which features wing flex technology to enable the full natural movement of the pelvis. This improves comfort and maximises pedalling efficiency and with the addition of fizik's comfort core foam and a microtex cover, the comfort level is enhanced even further.carbon fibre railsa high quality carbon reinforced shell isnt the only major plus point with this saddle, it also has braided carbon rails. These rails are strong and lightweight and combine with the shell to give you optimum pedalling efficiency.featurescover material microtexshell material carbon reinforced nylonrail material 7x10mm carbon braideduse roadopen central cutawayintegrated clip system compatibledimensions lxw regular 274x140mm large 274x152mmweight regular 185g large 190gbuy fizik components from chain reaction cycles, the world's largest online bike store.