It is designed to be pumped with a 12 volt tire compressor. A hand bike pump can be used in a pinch, but it takes a while, due to the high 65 PSI and the large size of the unit. A CO2 pump could be used as well.
It can also be filled and pressurized with just your garden hose by using the included female to female connector. No pumping required.
You can get longer run times by dialing the pressure back with the black handle on the elbow and/or the nozzle adjustment on the tip. Up to 10-15 minutes. The high pressure is good for cleaning gear. Dial the pressure back for showering.
If you fill it all the way up, and then pressurize it to 65 PSI, it is designed to run out of pressure about the same time as the water runs out.