LEER truck caps, also called truck toppers, truck canopies or camper shells, are constructed of strong, resilient fiberglass or tough non-corrosive aluminum. Most toppers are the same height as the truck cab; some models of leer caps are somewhat taller. Most truck bed toppers can accommodate a roof rack, adding to their cargo-carrying capacity. Fiberglass camper shells are painted using formulas that match those originally used by the truck manufacturer and preferred by residential customers. Aluminum caps are preferred by contractors, service technicians and others working in rugged environments.