The PetSafe PIG00-10673 Comfort Fit In Ground Radio Fenceis the newest offering from the world's best selling pet containment system manufacturer. It features a 10 acre transmitter with AC power supply, the lightweight PIG00-10679 receiver collar with one level of correction, 500 feet of 20 gauge wire (covers 1/4 acre), 50 boundary flags, a collar testing tool, installation manual and a training DVD. You can purchase additional wires and flags to expand your coverage area to up to 10 acres. You can put as many dogs as you like on one system as long as they are each wearing a receiver collar. Each kit includes one waterproof collar. All In-Ground Receiver Collars work with any In-Ground System or the Indoor Radio Fence. An unlimited number of pets can be added to PetSafe In-Ground Systems as long as they are wearing a compatible Receiver Collar. The new QuickFit buckle allows you to put the collar on or remove it in a matter of seconds. It also provides a perfect fit every time for added comfort. PetSafe PIG00-10673 Comfort Fit In Ground Radio Fence features: PetSafe 10 Acre Transmitter with AC Power Supply Warning Before Correction Stimulus. QuickFit buckle allows for a quick release and a perfect fit every time Receiver aprox. 2 1/2" x 1 1/4" x 1 1/2" weight 4.0 oz! Durable 100% Waterproof Receiver Collar Audible Wire Break Alarm built into the Transmitter for 24/7 Protection Correction Zone Width Control Knob, Adjustable from 3' to 20' in width 500 Feet of 20 gauge Factory packed Underground Boundary Wire Containment Fence will cover approximately 1/4 acres of land 50 Training Flags included Installation Manual and Training DVD Collar Testing Tool Initial RFA-67 Battery Included (6 to 8 month battery life) Safety Shut Off, Shuts your system off if your pet is in it for 20 seconds Asics Microchip Chip, Over 3000 filters to prevent unwanted correction.