yes they are low impedence...i dunno exactly what the box is, but i'm guessing its a driver or something i dunno...im goin to ask Rick at amazon tomorrow what it is.... and the reason for selling b/c i my car was pushing 20psi on race gas only and now i went to 13psi and more street friendly 60lb injectors... I bought the 60's from amazon racing and rick took these out and i have no use for them now b/c i sold my car yesterday. But they worked great when i did have them.