Features: Brand new and high quality Gigabit Ethernet interface has better electromagnetic performance. Three USB2.0 host interfaces can be used to connect a mouse, keyboard, or other USB devices, and one of them is a 1.25mm interface at the same time, which can be used to connect a CM4 module. On the basis of Gigabits, the dual-port CM4 expansion board expands the network via USB and simultaneously expands three USB2.0 host interfaces. 40-pin expansion interface is fully compatible with 40-pin RPi and can be used to connect various standard expansion accessories. It uses USB C and eMMC burning, which is suitable for all configurations of rpi CM4 boards. Supports 4K output. Specifications: Material: Aluminum Type: 5mm/11mm Size: Approx. 8x8.6x3.6cm/3.15x3.39x1.42inch Note: 1.Please allow 1-2cm errors due to manual measurement, make sure you don't mind before ordering. 2.Due to the differences between different monitors, the picture may not reflect the actual reality of the item. Package Includes: 1 Set of expansion board