The Dogtra E-Fence 3500 is an effective underground containment system with rechargeable a collar for mild to stubborn dogs. Set boundaries around your property that allows your dog to be safe in your yard. Features2-Hour Rapid Charge BatteriesFor Dogs 15 pounds and upNon-Stimulating High Performance Pager provides vibration before stimulationVibration Only setting for timid dogs8 Low to Medium Stimulation LevelsUltra-Compact Receiver/CollarFully Waterproof Receiver/Collar40-Acre Maximum Area CoverageWire Break Light and Alarm1-Year WarrantyPlastic Training ProbesOwner’s Manual & Training ManualIncludes:Wall Mounting TransmitterWaterproof ReceiverTransmitter Power AdapterBattery Charger for Receiver500 ft. 14 Gauge Underground Fence WireTraining Flags (50 each)Waterproof Splices (4 each)Test LightGround Wire (Dark Green)Transmitter Mounting Screws (2 ea) & plastic anchors (2 ea)SpecificationsSize: 16 gauge