The Rechargeable In-Ground Fence™ is the convenient containment system that lets you keep your pet safe in your yard without having to regularly replace collar batteries. Charge your pet's Receiver Collar when the battery's low and away he goes to enjoy his new yard  freedom. Add as many pets as you like with additional compatible collars. 4 adjustable levels of static stimulation plus tone-only mode for training lets you find just the right level for your pet. The fence installs in about a weekend with some basic DIY skills. You'll bury wires in your yard to set a custom pet area up to 13 ares with additional wire and flags. The Transmitter sends a radio signal through the boundary wire to your pet's collar. If your pet approaches the boundary, he'll hear a warning beep to remind him to stay in the yard. If he continues through the boundary, he'll feel a safe, gentle static stimulation from the collar to keep him in the yard. After about 2 weeks of training, your pet will quickly learn the areas he is free to enjoy. Specifications * For outdoor use only * For dogs and cats 2.3 kg and up * Fits neck sizes 15 - 66 cm * 4 adjustable levels of static stimulation * Tone-only mode alerts your pet with a beep * Over Stimulation Protection: Stimulation stops after 15 seconds * Covers up to 13 ares (1/3 acre/0.13 hectares) with included boundary wire * Expandable up to 1,000 ares/25 acres/10 hectares (additional wire and flags required) * Unlimited number of pets * Add an unlimited number of pets with additional in-ground Add-A-Dog® Receiver Collars * Run Through Prevention- Static Stimulation increases if your dog tries to run through the boundary zone * Waterproof Receiver Collar * Uses rechargeable batteries * Each charge usually lasts 1-3 months * Battery recharges in 14 hours * Good/low battery indicator