NRS Super Pump Built-in pressure gauge takes the guesswork out of inflating your boat or board This low-volume, two-hand pump lets you inflate to pressures up to 20 psi You get double-action pumping (inflate on both up and down motions) when you have the red plug screwed into the air port in the top cap, quickly put the majority of the air volume in your inflatable When you need higher pressure, simply open the air port by removing the red plug and you can bear down with single-action strokes Small diameter pump chamber keeps the pumping easy, even at high pressures