By Luna Pro gray, if you mean the older CDS type, no. Definitely opt for the Luna Pro SBC. Three reasons: 1. The SBC uses a common 9-volt battery. 2. The SBC is what I call one-step. Push the button, spin the dial until the needle is at the center, and directly read the f-stop and shutter speed. The older CDS is 2-step, where you need to read the number on the dial beneath the pointer, and then transfer it to the other dial. 3. The older CDS needs mercury 1.35 volt cells unless you have the adapter device. Most of the numbskull sellers on ePrey claim their CDS units are in "perfect working order." How do they know? Did they install mercury cells? I think not. If you really want once of the CDS units, buy a newer one in the black plastic case. Many of the gray ones are brittle and are disintegrating inside where screws attach the mechanism (I know from personal experience).