Selle Royal Scientia Relaxed Unisex Bike Saddle utilizes outstanding design based on a Scientific Research. This saddle is designed for ultimate comfort to perfectly fit the Relaxed rider. Those riders that ride up straight at a 90° angle with significant weight carried by the saddle. Padded with the 3D Skin Gel specifically positioned in the Central Reservoir to cushion the soft tissues, this saddle further avoids shocks thanks to the innovative Curva Suspension. R1 Small - for riders with less than 11cm of ischial variation. R2 Medium - for riders with 11-13 cm of ischial variation. R3 Large - for riders with more than 13cm of ischial variation.