Double-layer USB expansion port:Output 5V 1A Double-layer USB interface:They are I2C/UART functions Functionally based on ES32-WROVER (WIFI/Bluetooth) module, 5V relay, buttons, RTC, battery-powered interface, DC socket (5-12V input) battery-powered switch, USB expansion port I2C/UART, USB expansion port are designed The output power supply can supply power and control the current of equipment below 1A. The back side retains the TF card socket in the same position as the Raspberry Pi, which is a self-popping card socket, which is convenient for plugging in and out. Chip:ESP32-WAROVER LCD:3.5 inch capacitive touch screen ST7796 FT6X36/ILI9481 GT911 USB TO TTL:CH9102F Relay:HFD3 5V 2A Relay connector:5.08 DC-DC input:5-12V DC Block Specifications:5.5X2.1 TYPE-C input:5V USB output:5V 1A Battery Specifications:3.7V lithium battery Battery switch:Toggle Switches Button:RST button, custom button RTC:PCF8563 Extension pin:2.54 2X20 Colour:black Material:Plastic + Metal Package Contents: 1 x host 1 x line Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.