4ga. & 8ga. power and ground wires are good quality with heavy jackets and the wire gauge truly is what it is supposed to be unlike some other kits where the measured gauge size includes the jacket. The inline fuse holder is not for 4ga. wire like the kit says. It is for 8ga. wire. This makes no sense since the main power cable in the kit is 4ga. It looks like the fuse holder has an adapter insert so it can be used with 4ga. or 8ga., but when the 8ga. adapter is removed to insert 4ga. wire, the fuse holder does not seal together properly. I did not use the battery terminal (wasn't correct for Nissan Titan), dual fused distribution block, or ground distribution block. So basically, I just used the power and ground wire, remote turn-on wire, and RCA cables. The speaker wire is pretty lame, too.