Fussion 700 Air Pump is a very quiet pump; it puts out lots of air, and is adjustable down to a very low flow. It has two outlets which can power one or two HOG.5 units, or you can combine them into one outlet (using the included T fitting that we put in) to power one HOG1 or HOG1x. You can use the two outlets to power one SURF2, which has two air inlets. Or get two pumps to power one SURF4 which has four air inlets.