The PetSafe Play and Stay is a Wireless Dog Containment system.  Very simple and easy to use.

Wireless - sets up in minutes, just plug and play.

Extra Collar/Receiver for Stay+Play Wireless Fence

Intended for dogs over 5 pounds with a neck size between 6" and 23".

Fully Waterproof and rechargeable.

Features

Portable - can easily be used while traveling or taken to a new home if you move.
Safe and Secure - provides a safety zone that your pet won't run through, dig under, or jump over.
Instant installation - no burying wire.
Expandable - This system will support an unlimited number of collars (1 is included).


How it works: Simply plug in the transmitter somewhere inconspicuously in your home. It emits a radio signal around your home. Your pet wears a lightweight receiver collar which "listens" for the signal. While its receiving the signal, your dog is free to run and play. When it approaches the boundary of the signal area, it receives a warning beep. If it continues, it receives a light static energy pulse which is startling but not harmful.

With a little training that is simple and quick, your pet quickly learns its boundaries. Setting the boundaries of your yard takes only a few minutes. Since the signal can transmit reliably through walls or other household obstructions, it can be placed in any convenient and discreet location in your house, typically a garage or closet.