Liquid level alarms, timers, power failure alarms. Tank alarms feature the worlds only float protected inside a pipe for industrial durability. The Drum Alarm constantly monitors liquid level and gives an alarm when full or empty. Battery power lasts for years. Waterproof digital process timers count down from a set time and give a very loud alarm when a cycle is elapsed. Can control other devices. Power fail alarms let you know when there is a power outage.