WARNING!!: This is not a life-saving device! There is no substitute for constant parental supervision when a child has access to a pool or other body of water. This is an alarm. Made for Children ages 2 and up. One size fits all Shrill, very distinguishable sound (103dB) can be heard over 100 feet away Alarm is activated when Wristband gets wet Safety Latch prevents wristband from being removed by child Alarm cannot be heard when wristband is completely submerged under water.