Description 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, itâs 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.PRODUCT DETAILS:Expands up to 100 acres with purchase of additional Wire & Flag Kits (SDF-WF) Expands to any number of dogs with purchase of additional Collar Receivers (SDF-CR) Not compatible with the SDF-100A or SDF-CT Add-A-Dog collars (SDF-R, SDF-CTR) 1,000 feet of wire, 100 flags, and 1 Collar Receiver are included to keep your dog contained in a yard up to 1 1/3 acres Wire-break Transmitter alarm alerts you to possible problems with the Boundary Wire Anti-Linger Feature prevents dog from running down Collar Receiver battery in warning zone Built-in lightning protection