Expansion board parameters: The design of the Zero 2 board with pin insertion makes it easy to insert. The interface position is easily compatible with the Raspberry Pi 3B series (3B / 3B+) motherboard. The module has an onboard USB audio headphone port and an additional speaker port. The onboard 4-channel USB expansion port is compatible with USB 2.0 / 1.1 transmission. The onboard RTL8152B Ethernet chip supports 1-channel RJ45 network port, 10/100M adaptive. Only compatible with Zero 2, not Zero.