The Dogtra e-Fence System gives you the ability to allow your dog the freedom he wants, within the premises of your property. Dogtra's containment system contains your dog without the use of conventional fencing that can be chewed through, jumped over or dug under. The system comes with a 500 foot spool of wire. The collar/reciever are both waterproof. There is a Pager/Vibration feature which warns the dog prior to any stimulation. This feature also allows you to control the adjustable intensity to best suit the personality of your dog. The signal has a long-range of up to 40 acres. The EF3000 has a rechargeable reciever and user-friendly controls. These systems use state-of-the-art microcomputer technology which prevents reception from any outside sources interrferring with the system. Additional reciever/collars can be purchased for multiple dogs.