... There are 3 super functions for this machine.( dog or cat repeller and training, flashlight) How to work: 1. put ... 3 seconds , the machine can be used in dog or cat training with fixed lower comfortable ultrasonic wave. 3. ... few seconds , the machine can be used in dog or cat repeller with variable higher comfortless ultrasonic wave. ... , 1pc 9v battery , three in one case. electronic dog training