Built-in and stable ESP32-WROOM-32E module, large capacity 4M Flash; The I/O port of the ESP32 module and the UART program download port are all led out to facilitate secondary development; Built-in ESP32 module IO0 programmable button and reset button; ESP32 supports the use of IDE development tools and provides reference programs in the development environment; Built-in 8-way 5V relays, output coupling signals, suitable for controlling loads with operating voltages within AC250V/DC30V; built-in 1 programmable LED and relay indicator. Type: module Supply Voltage: DC5V-30V Material: PCB Color: blue Size: 148 x 79.8 mm Package Contents: 1 x Relay Module 2 x 10 Double Row PIN 1 x 6 Single Row PIN Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowed measurement error is +/- 1-3 cm.