The Techko S189D Ultra Slim Pool Safety and Entry Alarm is an ETL listed and approved under UL 2017 standards. This child safety pool alarm is designed to sound a loud alert when a door or gate is opened. It is a simple solution for alerting you whenever your children and others enter and leave the pool area. This unit includes two pairs of magnetic contact sensors and a remote bypass button, ideal for pool areas with two gate or door entrances.