Terrapin Communications’ Safety Turtle wireless door alarm DA-101 mounts next to any door that provides access to backyards.Alarms sound at the base station. The system supports any number of wristband, gate and door sensor-transmitters of the same color. The compact unit operates for three years on a CR2032 coin-cell battery (included) and is UL 2017 compliant.www.safetyturtle.com(613) 271-0050