1. Lead out all 10 digital ports and 10 analog ports, each with a standard positive and negative power interface. 2. Lead out the 12C interface on the motherboard for easy connection with I2C devices. 3. Add a DC power interface. The actual power supply of the USB interface on the For Nano board is only 50MA. 4. When it comes to high-current devices such as servos, the power supply is insufficient. At this time, the DC power interface provides external power to stable operation of the equipment. 5. This expansion board is a must-have for any for enthusiast or professional who wants to expand the of the project. Simple installation and sturdy structure, designed to improve the performance and scalability of the project. Output: 3.3V output Pins: 6 PWM Pins Input: 1 servo power input Extension: I2C expansion Pin Due to different batches, the appearance and printed text of the product , but it will not affect the use Colour:As Shown Material:plastic Package Contents: 4 x Expansion Sensor Shield Module 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 a little different from the real thing. The measurement allowed error is +/- 1-3cm.