Simply 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 pressure Accordion-style hose stretches to five ft. long and interlocks to the pump so it doesn't fall off while you're pumping Very effective for "topping off" large towables in the boat, since peak pressure is an impressive 14 psi This double-action pump inflates and deflates towables, kayaks, boats, airbeds and other inflatables Delivers a continuous stream of air on both the up and the down strokes Four universal valves are included to fit Boston valves and stem valves Volume is two liters/stroke. AIR PUMP HAND AIRHEAD