The SportDOG BrandA(R) 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 1000 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 DryTekA(R) technology - waterproof and submersible to 25 feet. SPECIAL FEATURES 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-DogA(R) collars (SDF-R SDF-CTR) 1000 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 MORE INFORMATION The system works by producing a radio signal and sending it from the Fence Transmitter through the Boundary Wire. The Collar Receiver can identify that radio signal and will send a warning and/or correction when it picks up the signal. Bury the Boundary Wire to enclose the dog's Boundary Area. Temporarily define the Boundary Area with Boundary Flags for a visual aid in training your dog. Your dog wears the Collar Receiver with Contact Points that touch his neck and once trained can roam freely in the Boundary Area. When your dog reaches the Warning Zone the Collar Receiver gives a warning beep/vibration. If your dog continues into the Stimulation Zone (closer to the wire) a safe static stimulation will be delivered through the Contact Points to get his attention until he returns to the Boundary Area. STIMULATION RANGES 7 levels of static stimulation to match any dogs? temperament Option to train with vibration and tone EXPANDABLE SYSTEM Vibration/tone warning WATERPROOF Waterproof and submersible to 25 feet using DryTekA(R) technology DOG SIZE For dogs 10 pounds or larger BATTERIES Rechargeable lithium-ion batteries Charges in 2 hours lasts 1-2 months per charge LOW BATTERY INDICATOR Yes CONTENTS Fence Transmitter with Adaptor Collar Receiver with Charger 1000 Feet of Boundary Wire Operating Guide Test Light Tool 100 Boundary Flags Long Probes 2 Wire Connectors Built-in lightning protection PRODUCT DIMENSIONS Receiver without strap - 2.60"L X 1.30"W X 1.23"D