Well, there are two types of it. One is 12v type, which can be used through car's 12v cigarette lighter socket..... all you need is a bucket of water and that 12v pressure sprayer, and it will pump the water from bucket and spray it through the hand gun/nozel, but what I am using is a manual one, have to pump it by hand and then it sprays through the nozel ( i preferred that because it was easy to carry anywhere i want where car is parked and wash it there and i don't need a separate bucket full of water for that). It does the job okay for mild to moderate dust/dirty car, but for heavy dose, you need full pressure like from a garden hose or car wash.
this is the one i am using and am satisfied with it, washes a mild to moderate dirty car with one tank (8L).
