The SportDOG Brand® SDF-100C In-Ground Fence™ System features a smaller and sleeker Collar Receiver than the original In-Ground Fence system (SDF-100A). The collar features a Li-Ion battery that charges in two hours and has a one to two-month battery life. Now featuring seven levels of static stimulation as well as vibration and tone, it’s easier than ever to keep your dog safe and secure. With 1,000 feet of wire and 100 flags, you can contain an area as large as 1 1/3 acres (or up to 100 acres with the purchase of additional wire and flags (SDF-WF)). Multiple dogs? Simply purchase additional collars (SDF-CR). Dependable in any environment, the collar uses DryTek® technology – waterproof and submersible to 25 feet.