PetSafe's PUL-275 UltraLight Receiver is the world's smallest receiver. It uses a RFA-67D-11 battery (included with every receiver). It has 5 correction levels that are adjustable on the collar itself. It's recommended for dogs 8 to 60 pounds. Best used with easy to train dogs.
The PUL-275 UltraLight Receiver is a replacement collar for the PetSafe PRF-304W Deluxe Radio Electric Dog Fence, but is compatible with all PetSafe in-ground fences.
