①. RF433 Battery-free Remote Control Wall Light Switch: Self-powered wireless switch, no wiring required, wall panel transmitter. DIY smart switch RF433Mhz wireless remote control, stand-alone wall panel transmitter, works with Alexa Google Home, provides a switching user experience. ②. Packing List: One receiver with one transmitter. Note: There are different products in the package when you choose another option. 2 * Double-sided tapes for each transmitter. ③. Receiver Specifications: Model Number: KR2201-4. RF working mode: Superheterodyne reception. Modulation mode: ASK. RF frequency: 433 MHz. Input voltage: AC 85V~250V. Quiescent current: 5 mA. Remote control distance: >50 m (free space). Output terminal: NO, COM, NC. ④. One switch controls multiple receivers, and multiple switches control one receiver. Stick it wherever you want. ⑤. Works without WiFi/battery: With the self-powered function of the switch, it works with the receiver to control connected devices without WiFi or battery. The signal can be transmitted through the wall. Indoor: up to 30m. Outdoor: up to 100m. ⑥. Toggle Button: Unlike the traditional button, the toggle button makes your life easier and more convenient. Collect power from your finger. No battery required. No wiring required. ⑦. Overload protection NOTE: Both must be purchased and used together. Choose the number of receivers and controllers according to your usage scenario.