The unique design & material of the Exalt Tank Cover allows the one size to be used on multiple sizes of carbon fiber tanks. Features a non-stain material that provides superior grip. Minimalistic low profile & low weight design. Multiple surface finish design & added thickness at the bottom protects your tank while looking fresh! The Large will fit 68, 70, 72 and 77 ci carbon fiber tanks. The Small fits 45, 48 and 50 ci carbon fiber tanks.