This PetSafe(r) extra receiver collar can be used to add another dog to any PetSafe in-ground fence system or as a replacement collar to the Stubborn Dog In-Ground Radio Fence. Designed for stubborn or hard-to-train pets 4 levels of correction, plus tone-only option Uses 9-volt alkaline battery (not included) Waterproof Weight includes receiver, collar strap, battery and contact points
