Compact aerodynamically shaped seat bag for essentials 3M reflective material for increased visibility and road safety Long wearing Denier nylon and Dupont Teflon construction Intended for use with the Prologo U-Clip system Also Compatible with the Topeak QuickClick system U-Clips sold separately U-Clip 2.6x5.82x3.2` 41 c.i. Black Small (1-100 c.i.)