Hi, I wanted to use a Nikkor zoom lens in my housing, no zoom ring was available, so I made my own with a gear belt. I wrapped the
zoom ring with a rubber strip cut from an inner tube, taped it with 3M black electrical tape, and mounted the gear belt on it.
The gear belt I cut with a sharp razor, on a bevel, and sliped the two ends togeth with thin wire (paper clip wire). I have used it for
two seanns, made one for my dive buddy as well. Words fine
The Ebay link for the gear belt is here. Good luck and great diving!