I just bought a ring type with digital display, its the ultrainflate 20 , and is very good with a clear display and preset pressure setting and good cable and hose storage, however it takes about 12A and it took out my cars' atc fuse for the cigar lighter socket so I had to uprate it to 15A and changed the socket/plug for the DIN ISO 4165 type, a bit naughty but given the infrequent use it will get it will be fine . I have also fitted the same type outlet socket rated at 20A on the caravan's side to power various 12V devices in awning .As I use the pump a lot when working on caravans I have fitted the 20A connector to it and run it off my 280 A.hr battery /inverter system which I use to run caravan 240V systems. and also test the road lights I found the standard 12V connectors poor quality and get very hot when running at about 5-10A.