Mounting ring used to attach the scuba diver window in Stern's James Bond 007 pinball machines (assemblies 511-5986-00 & 511-8867-01).
Also used in AC/DC Luci & vault edition pinball machines to attach the lower playfield window (545-9980-00) to the main playfield.
This product may have additional uses in other pinball machines as well.
Stern #545-9991-01 (replaces #545-9991-00).