This extra receiver collar can be used to add another dog or as a replacement collar to the STAY & PLAY® Wireless Fence with Replaceable Battery Collar, STAY & PLAY® Compact Wireless Fence or the Wireless Pet Containment System. This STAY & PLAY® Wireless Fence Replaceable Battery Receiver Collar includes 5 levels of static stimulation plus tone only mode adjustable to your pet’s temperament.