Features 1、ESP8266 CHIP: The relay module uses the ESP8266 chip, which can realize the wireless control of 4 relays in the local area network using the mobile phone APP with a simple configuration process. 2、WIRELESS CONTROL: You can control the switch anytime and anywhere in an open environment. When the mobile phone is mounted on the chip, the maximum stable transmission distance is 100m, and the indicator light can be selected in the onboard mode. 3、2 WORKING MODES: The module has 2 working modes, one is that the mobile phone is directly mounted on the ESP8266 chip, and the other is that the mobile phone and the ESP8266 chip are mounted on the router at the same time. 4、POWER OFF MEMORY: Use for Smartconfig technology to complete the configuration of the account and password of the ESP8266 chip on the mobile APP. The configured account and password have a power off memory function. 5、LONG SERVICE LIFE: The relay module can continuously pull in 100,000 times, has diode effusion protection, and has a short response time. Specification Item Type: 4 Channel Relay Module Material: PCB Package List 1 x 4 Channel Relay Module