Try he

http://doctorled.com/p2.htm

Does the 25 bulb fit the 20 base?

I bought the 40 two years ago when they (Dr.LED) first came out. I am
very happy with mine. Very low draw ... 70Ma and easily the most
noticible of the bunch when at anchor. Contact points are gold plated,
the "bulb" portion is a glued clamshell protective covering. - nice
gear.

Hi all,

I have an Aqua Signal Series 20 masthead light. It uses a small Halogen
Bulb 12V/5W. I would like to replace that with a led bulb. Anyone knows
where to get one of these?

Thanks,

Jeannette