Innotek Rechargeable In-Ground Pet Fencing System Rechargeable in-ground fencing system keeps pet safely in yard Run-through prevention; 24/7 built-in battery backup; 25-acre range Boundary self-check with audible and visual wire-break alarms 500 feet of wire and training DVD included; collar fits neck sizes 8 to 21 inches Measures 1-7/8 by 1-2/7 by 1-1/6 inches; limited lifetime warranty