This durable frame pump with switchhitter head automatically adjusts for schrader or presta valve tubes and shows pressure on a rotatable gauge switchhitter head works on schrader or presta valves with no disassembly gauge body rotates for easy viewing durable plastic barrel with aluminium shaft to reduce flex and improve efficiency plunger locks to body chamber with a simple twist for secure storage water bottle boss mount included max pressure 120psi 83bar volume per stroke 484cc