Smart Wireless Selfpowered Waterproof Doorbell Chime Elderly Caller 1*transmitter 1*receiver Features: No battery self-generation, just press the button and kinetic energy will be converted into electric energy (Pressing force is stronger than that of traditional doorbells to ensure sufficient generated energy). Large button design with long lifespan, sensitive and convenient e. Long-distance wireless working range, can reach a maximum value of 550in in open and batter free environments. IP47 waterproof and dustproof, no worry about wind and rain. Quick and easy installation without requiring wiring. Installation Steps: 2. Tear off the double-sided tape on the back of the doorbell button. 3. Install the doorbell button on the door and the installation is completed. Specification: Condition: Material: ABS No. of Music: 32 Waterproof Level: IP47 LED lights Mode: light off, chime+flash, flashlight Package List: 1 * Self-powered Transmitter  Note:Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.