Fast, simple do it yourself installation. Absolutely harmless to your dog. No unsightly fences, posts or transmitters. Safety and security for your pet. Easy, 3 step installation. For yards up to 25 acres in size. Features redesigned interior wall mounted transmitter. Totally waterproof rechargeable collar receiver looks slimmer and shapelier on your dog. Patented run through prevention and timeout between corrections help your dog learn his limits quickly and safely. Boundary self check displays system status 24/7. Battery back up (AA batteries not included) and recharge reminder transmitter with audible and visual wire break alarm, 1 rechargeable collar receiver with neckstrap, boundary wire, training support 800 number, complete installation instructions, video, training flags, and accessories.