This double-action pump from Airhead inflates and deflates towables, kayaks, boats, airbeads, and other inflatables with a continuous stream of air on both the up and down strokes. Simply turn the release valve counter-clockwise, and you're pumping air only on the down stroke. This is a great option when your inflatable is almost full, and there's back pressure. Four universal valve fittings are included to fit Boston valves and stem valves. The accordion-style hose stretches to 5' long and interlocks with the pump. Pumps 2 liters of air per stroke. Very effective for "topping off" large towables while boating.