Sevylor Dual Action Hand Pump
Here's what other sites are saying:
This is one handy hand pump it is capable of producing 66 Gallons @ 60 Strokes, Double action means it works on both the up and down strokes, pump is a high volume high pressure 4 liter pump. Pump comes complete with universal valve fittings, and will also deflate. It also can be converted to a bilge pump, now that's handy!