Set of 2 Pestbye Motion Activated Battery Operated Electronic Ultrasonic Outdoor Cat Deterrent ULTRASONIC SOUND SYSTEM - Effective system that repels cats and larger animals, without harming pets or humans. RANGE - 40 ft motion sensor operating range, depending on conditions RAINPROOF, VERSATILE AND EASY INSTALLATION - Simply instert the batteries and push into the ground of your backyard or garden. Alternatively the PestBye product can be screwed onto a wall or fence. REQUIREMENTS - Four AA batteries per unit. Battery life depends on how many times the device is activated, but we expect 3-4 months assuming 10 activations per day. Batteries are not supplied as standard. 2 UNITS AT A REDUCED PRICE!