Watch Programmable Development Module Board ESP8266 PCB WIFI Watch Board with Strap Without DC 3.7V 1. Small in size and exquisite in appearance, the programmable development module is convenient and beautiful to wear. 2. The development board is used for the development and control of embedded system. 3. The board is easy and simple to use and operate. Just connect the USB cable and connect to the computer, open the serial port driver folder, and install the CH340 driver. 4. High quality material can make sure the durability and stability of the product. 5. Precise production process and fine craftsmanship endow the board with good contact performance to stable work. Item Type: Programmable Development Module Working Voltage: DC 3.7V Battery Type: Polymer Lithium Battery (without Battery) Battery Capacity: 500mAh (without Battery) Purpose: For The Development And Control Of Embedded Systems Colour:black Material:PCB+electronic components Package Contents: 1 x Programmable Development 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.