Selle Italia Flite Boost Gravel Saddle. Features: TI 316: 7mm rails are hollow titanium, a balance of strength and light weight Manganese: 7mm rails made of a Manganese and CrMo alloy for excellent durability and value Fibra-tek: Selle Italia's latest cover material offering supreme durability and comfort For more information on idmatch visit http://www.selleitalia.com/en/idmatchsystem/ L3: "Wide" intertrochanteric distance and high pelvic rotation (Flow and SuperFlow saddles) S3: "Narrow" intertrochanteric distance and high pelvic rotation (Flow and SuperFlow saddles) Specs: Model: Flite Boost Gravel Idmatch: L3 Rails: TI 316 Top: Fibra-Tek Color: black Lx W Mm: 248x145 Weight: 232g