Anchor light
Mike I saw your post and said I can save this guy a wasted trip up the mast( like I made). When I replaced the light on my 83 cat 30, I bought a spare.However, the only number on it is 90 or 9d. It's about 1/2 inch across,about 1 1/4" long and two contacts on the bottom. Sorry I could not find a model or seial number for you. Good luck. Bruce CainSirocco