Based on the 40PIN design, it can be directly inserted. As a test board, test whether all pins of 3B/4B/CM4 are . As an expansion board, this module includes LED, basic functions, you can get started easily. This is a simple expansion board, suitable for beginners of . for 3B/4B hole, can also work on zero. Comes with demo code and guide for easy use. The onboard ADDA chip can read signals as a sensor expansion board and can send out DAC signals. Onboard industrial wiring terminal female port, the terminal has interface definition stickers. It is more beautiful and practical. Type: expansion board Colour:Photo Color Material:PCB Package Contents: 1 x Expansion Board 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.