Advantages: Easy carry watch, super light and comfortable material 315mhz protocol, work with almost all 315mhz alarm system Long work distance (15 to 30m indoor, 100m outdoor) Super power save, long work time (normally more than 12 months) Application: Home, hospital, old people, kids... Specifications: Technical Parameters: 315Mhz, EV1527, 430K Working Voltage/Current: DC 3V/13mA Transmitted Power: 10mW Modulation Mode: ASK Woke Mode: Send out alarm signal in 0.8s after triggered (avoid false alarm) Work distance: 15 to 30m indoor, 100m outdoor Power supply: 1 x C2032 battery (include), work time more than 12 months for normally use Work Temperature: -25℃~+75℃ Size: 46.5x42x15.5(mm) Weight: about 100g Color: red+white material: plastic Package Contents: 2 x Elderly Pager Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.