Features: 1.The wireless SOS button is mainly used in conjunction with the 433Mhz, 1527 code alarm host. 2.It is used for the elderly for help, doorbell buttons, etc., combined with the host's full wireless transmission, wireless transmission distance of 200 meters. 3.Waterproof, anti-pressure, anti-collision automatic control equipment features, safer and more secure. 4.The shape is small, easy to carry and convenient to use. 5.With emergency button function. Battery life is up to 3 years and no replacement is required. Specification: Features:_x000D_ _x000D_ The wireless SOS button is mainly used in conjunction with the 433Mhz, 1527 code alarm host. _x000D_ It is used for the elderly for help, doorbell buttons, etc., combined with the host's full wireless transmission, wireless transmission distance of 200 meters. _x000D_ Waterproof, anti-pressure, anti-collision automatic control equipment features, safer and more secure. _x000D_ The shape is small, easy to carry and convenient to use. _x000D_ With emergency button function. Battery life is up to 3 years and no replacement is required. _x000D_ _x000D_ Specifications:_x000D_ Condition: Brand New_x000D_ Material: ABS_x000D_ Color: White_x000D_ Effective control range: 200 meters;_x000D_ Transmission frequency: 433mhz_x000D_ Working voltage: 3V (CR2032);_x000D_ Quiescent current: 0;_x000D_ Transmit code protocol: 1527 protocol;_x000D_ Packing: 6.3*3.5*1.5CM_x000D_ Weight: Approx.18g/0.6oz_x000D_ _x000D_ Package List:_x000D_ 1 * SOS Button(Built-in battery)