Aerodynamic styling, four different sizes, with QuickClick(TM) mounting system.AttachmentsQuickClick(TM) (F25) w/Seatpost StrapCapacity0.98-1.31 L / 60-80 ciMaterial1000 Denier NylonExpandingYesSeatpost DiameterFits 27.2 - 34.9 mmAdded Features3M(TM) Reflective StripSafety Light Clip* 3M(TM) is a registered trademark of 3M Company.Size (L x W x H)20 x 10.5 x 12 cm7.9" x 4.1" x 4.7"Weight135 g/ 4.75 ozArt.no.TC2252B