Specification: Item Type: Alert System Material: ABS Receviing Distance: Approx. 330m / 1082.7ft Open Area Frequency: 433MHZ Method: 1 to 1 Built in Battery of Remote Control: 1 x 23A, 60mAh Alkaline Battery Package List: 1 x Alert System 1 x Button 1 x Manual Medical Alert Bracelets & Devices Health