This is a very humanized design product which suitable for babies potty training.It comes in an armband with an included alarm, which has high sensitivity of wet. Place or clip the sensor to where the moisture will be detected, and it will alarm you to help your baby to the bathroom. No more bed wetting, you might have restful nights and less laundry after having such a good item. Adjustable elastic armband to ensure a comfortable fit.After the alarm was activated, there is a voice and gently vibrates to let you know.