The CEX is designed specifically to repel animals such as mice, rats, possums, rabbits and wallabies from houses, aviaries, food stores, warehouses and gardens. The CEX emits a range of sound frequencies from sonic (which people can hear) right up to ultrasonic (which the pests hear but humans can't).
The sounds project from the CEX's inbuilt speaker and is effective up to approximately 25m (sometimes more). An additional remote speaker (an optional extra) can be plugged into the CEX thereby effectively creating two machines and doubling the area covered. The speaker can be placed up to 30m away from the base unit.
Always try to place the CEX (and speaker if applicable) at the same level as the animal you wish to repel i.e., for rabbits a couple of inches off the ground, wallabies perhaps a foot (30cm) off the ground, rats and mice - on the ground.