PetSafes Pawz Away Threshold Barrier prevents your furry friend from going into certain rooms in your home or keeps them away from staircases without the need for physical gates. The transmitter creates an electronic fence that sends a signal to your pets collar, which triggers a series of beeps and a progressive static correction. It is designed to startle, not to punish, so your pet learns to stay away from the area. One collar works with multiple transmitters, and multiple collars work with one transmitter (extra collars and transmitters sold separately). Features training and standard modes. Adjustable nylon collar fits pets weighing 5 lbs. or more with neck sizes 6 to 28. Works best for pets less than 40 tall. Transmitter requires two 3-volt lithium batteries (included). Includes one transmitter and one receiver collar. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Electronic Collars.