Quote Originally Posted by stephen
I'm still using an original Lunasix that I bought 40 years ago. Gossen make an adaptor that converts it from Mallory PX13 mercury batteries to the modern silver ones.
I found a replacement called a Wein Cell MRB625 at B&H. It comes with a collar adapter as well. It's described as a Zinc/Air battery. I don't know if it will last as long as the PX13. I'll let you know in about 10 years.