The Innotek SD-3125 Contain 'N Train Receiver Collar is compatible with the SD-3000 and SD-3100 in-ground dog fences. It can be used to add a dog to an existing system or to replace an old receiver collar. The Innotek Contain 'N Train Receiver Collar is lightweight, waterproof and adjustable, and is powered by a 6-volt battery.
Note: The SD-3000 can only operate one Contain 'N Train receiver and the SD-3100 can handle two receivers. Additional dogs can be "contained only" with the SD-2025 receiver collar.