When the WiFi module and the mobile phone are connected to the same router, the transmission distance depends on the router's signal strength. Onboard 12V, 10A // 250V AC 10A // 30V DC relay, capable of 100,000 continuous operations, with diode discharge protection and fast response time. Uses Smartconfig technology to complete Wi-Fi account and password configuration via the mobile phone app for the ESP-01 WiFi module, supporting username and password memory function. Features single board mode selection and real-time working status indication. Includes reserved UART debugging interface and STM8 SWIM programming download interface. The 12V dual WiFi relay module integrates the ESP-01 WiFi module and is compatible with 8-bit MCU chips. With a simple setup, enables wireless control of two relays via mobile app. Onboard ESP-01 WiFi module and high-performance STM8S103 microprocessor. The module supports two operation modes: Mode 1: Mobile phone connects directly to the WiFi module. Mode 2: Mobile phone and WiFi module are connected through a router. Additional feature: When the ESP-01 is removed, the module can still function as a USB relay. Transmission distance: In open space, when the mobile phone connects directly to the WiFi module, the maximum stable transmission distance is up to 100 meters. Note: The color of some components may vary slightly, but functionality remains unchanged. Color: blue Material: metal Package Contents: 1 x ESP8266 12V WiFi Relay Only the above items are included; other accessories are not included. Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error allowance is +/- 1-3 cm.