Also the adapter was a pain in the ass to get hold of for some reason. Had to go to about 5 stores before I got the right one. You can get 500mA 1000mA 1500mA i'd imagine the more mA the more you can run off it. Got the 1500mA so the speed isn't compromised with three fans feeding off it. Cheap to buy and its got a shit load of different voltage settings on the back. Pretty handy.