Features: Brand new and high quality Gigabits Ethernet interfaces have better electromagnetic performances. Three USB2.0 host interfaces can be used to connect a mouse, keyboards or other USB devices, and one of them 1.25mm interfaces at the same time, which can be used to connect a CM4 module. On the basis of Gigabits, CM4 double port expansion board extends networking through USB, and at the same time expands three USB2.0 host interfaces. The 40pin expansion interfaces is fully suitable for the 40-pin of RPi, and can be used to connect various standard expansion accessory. It adopts USB C and eMMC burning, which is suitable for all configurations of rpi CM4 board. Support 4K output. Specifications: Material:Aluminium Type:5mm/11mm Size:Approx.8x8.6x3.6cm/3.15x3.39x1.42inch Package Includes: 1 Set Expansion Board note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual of the item.