Serfas RX Saddles are designed to increase blood flow and alleviate numbness. If you're looking for the best in comfort and protection against any perinial issues, the Serfas RX is your saddle. The new RX-RR saddle is our lightest RX saddle to date. Inspired by racers, this saddle has all the performance benefits of our RX design but brings them to you in a sleek and nimble package.