In-Ground Fence for Little Dogs – Designed to fit dogs 2.3 kg and upCovers Up to 1,335 square metres with Included Wire – Can be expanded up to 101,171 square metres acres with the purchase of additional wire and flagsAdjustable, Waterproof Receiver Collar – With 4 levels of static stimulation and tone only mode for training, receiver collar can be adjusted to dog’s temperamentAdd Unlimited Pets to Your System – Keep as many pets as you need safely in your garden with this add-a-dog receiver collar. Compatible with all PetSafe®In-Ground Systems except YardMax® and UltraSmart®.