The overhauled 4U, 6U, and 8U Roto Rolling Racks incorporate an innovative new design that includes our new one-touch pull handle and back lid mounted wheels for easy transport. The exteriors have been upgraded too to allow the new Roto Rolling Racks to easily stack with existing SKB standard and shallow racks. Four military grade butterfly latches secure each lid with an internal rubber gasket that keeps water out so sensitive electronics stay safe and secure in transport.