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: The wireless SOS button is mainly used in conjunction with the 433Mhz, 1527 code alarm host. 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. Waterproof, anti-pressure, anti-collision automatic control equipment features, safer and more secure. The shape is small, easy to carry and convenient to use. With emergency button function. Battery life is up to 3 years and no replacement is required. Specifications: Condition: Brand New Material: ABS Color: White Effective control range: 200 meters; Transmission frequency: 433mhz Quiescent current: 0; Transmit code protocol: 1527 protocol; Packing: 6.3*3.5*1.5CM Weight: Approx.18g/0.6oz Package List: 1 * SOS Button(Built-in battery)