The PF-1000 Pet Containment System by Educator® is a safe and humane way of effectively containing your dog safe without the need for an actual physical barrier. Features include: Support for multiple dogs 30 different stimulation levels Over-stimulation prevention Run-through prevention Anti-linger feature to save battery life Tone only option for highly sensitive dogs The PF-1000 comes with one collar/receiver. Collar/receivers are waterproof and shockproof and employ quick charge Li-Polymer batteries. Perimeter wire, training flags and additional collar/receivers sold separately. NOTE: PF-1000 collar/receivers are not compatible with remote training system transmitters.