This easy fence system keeps your dog safe inside an area up to 210-feet in diameter through a transmitted signal; no wires need to be buried underground! Perfect for a smaller backyard or to take with you when traveling. The wireless system comes with a central transmitter unit, 23" long collar (can be cut down to size) with two sizes of correction prongs, recharger, 50 perimeter warning flags, and a training guide. Transmitter must be kept in a protected area. Dog collar has five levels of correction and a warning light if collar needs recharging (a charge lasts approx. 3 weeks). Suitable for dogs over 5 lbs.