PetSafe Pawz Away Indoor Pet training Barrier Transmitter, Adjustable Extra transmitter for Zones systems ZND-1200 and ZND-1300 Instantly keeps the dog away from problem areas in the home No training or installation required; simply place in area dog should avoid Protects an area from 2- to 12-feet in diameter; runs on 3 AA batteries Measures 4-3/4 by 4-3/4 by 1-1/8 inches; limited lifetime warrant