All 5/16″ hex head for handy socket wrench/nut driver tightening.2. Special band design to protect your hoses. Safe sealing and last longer.4. Ideal for auto repair, gas line, radiator, silicone heater hose 5/8 and 3/4″, fuel line hose 1/4, 5/16, 3/8 and 1/2″ID.