Ideal-for-every-terrain 45mm rim depth with a significantly wider internal width to provide greater performance and ride quality in almost every measurable way Optimized for top aero performance with a 28mm tire but capable of handling gravel tires up to 50mm wide 27mm outer width, and 23mm internal 76 / 176 DB hubs with Center locking interface SRAM Model ID: WH-303-STLD-A1