I wanted to convert my old mercury pole to metal halide so I could have a good selection of incandescent bulbs and not be able to buy mercury ballasts in places where vapor is gone. I had to replace both the lamp holder and ballast so this was a must. Easy to install with a few simple nuts and washers and a good wiring diagram on the box (like other Leviton products). The wires were nice and long and the build quality was good. 5 stars from me, I got what I expected.