Perimeter Technologies Receiver Battery Information:
These Invisible Fence compatible batteries work with the R21, R22, R51, and MicroLite fences. The batteries are very durable and long lasting so you get the most out of each Invisible fence replacement battery. The rugged design makes it so the battery won't come out whether scratching at it or wrestling about the battery will remain secure.
Designed to last up to 6 months
Very long Long shelf life - so stock up with a 3 pack!