This CatStop from Eyenimal will help keep cats out of gardens and other outdoor areas without using chemicals or sprays. The unit gives off ultrasonic burst for 20 seconds every 50 seconds, 3 minutes or 5 minutes. It also emits a flash of light. The unit can be mounted on a wall or placed on the included ground stake for easy installation. Operates on 3 AA batteries. Note: Ultrasonic tones may not affect certain exotic breeds and older cats that may be hard of hearing in the upper hearing range