http://www.hobby-lobby.com/mini_fan_..._1515_prd1.htmi got it off graupner a few years ago this is what it looks ike but it says for 48- size moror? mine might be a bigger moddle they dont sell any more.. . yeah its a graupner 600 bb turbo brushed motor 9.6 volt it puts off a fair amount of thrust. i have a feigo 540 7xl to use, what is a good rpm for EDFapplication so i know if it will be appropriot on 4s.