Feature: 1. WITH LED INDICATOR: With 4 way LED indicator, you can directly use the LED working status to indicate the program, which is convenient for debugging. 2. MULTIPLE DISPLAYS: 4 digit digital tube display, which can be used for digital display experiments, and display temperature, voltage, counter value, etc. 3. FOR WIRELESS DEVICE: Bluetooth, wireless interface, voice module, voice recognition module can be used for wireless communication experiments. 4. GOOD COMPATIBILITY: Can be seamlessly connected with mainstream controllers such as for LENARDO 2560 on the market, which has good compatibility. 5. WIDE APPLICATION: With accurate adjustable potentiometer, providing analog port input, can be used to control LED brightness, rotate the servo angle and digital voltage, etc. Specification: Item Type: Multifunctional Expansion Board Board Size: Approx. 70 x 50mm / 2.8 x 2in Temperature Sensor Interface: LM35 can do temperature measurement experiments. Package List: 1 x Expansion Board