This PetSafe Wireless Stay & Play Rechargeable Collar Receiver lets you add a collar to your your existing Stay & Play Wireless Fence or PetSafe Wireless Fence PIF-300 System. It replaces the PIF00-12918. The Stay & Play Collar is designed for pets 5 pounds and up, with neck sizes 6-23 inches. The waterproof receiver collar offers six levels of correction including tone-only mode. Just plug the collar in and the quick charge will be ready in 2-3 hours. A full charge should last up to 3 weeks. .