Can I use this in my Nikon FM3A Camera?
Yes but you only need one. I've had one in my Nikon FE for years. Lasts forever it seems.
Thank you, Daniel.
I used the Lenmar WCCR13N in my Nikon FE2 but I believe the FM3a uses a single DL 1/3N or 2 A76, S76 batteries
I have no experience with Nikon equipment. Check your manual. Call Nikon. Sorry, I can't help.