This double-action pump inflates and deflates towables, kayaks, boats, airbeds and other inflatablesDelivers a continuous stream of air on both the up and the down strokesSimply turn the release valve counter-clockwise and you're pumping air only on the down-stroke; a great option when inflatable is almost full and there is back pressureFour universal valves are included to fit Boston valves and stem valvesAccordion-style hose stretches to five ft. long and interlocks to the pump so it doesn't fall off while you're pumpingVolume is two liters/strokeVery effective for "topping off" large towables in the boat, since peak pressure is an impressive 14 psi