Raspberry Pi Zero 2 W offers 2.4GHz 802.11 b/g/n wireless LAN and Bluetooth 4.2, along with support for Bluetooth Low Energy (BLE), and modular compliance certification. The board has a microSD card slot, a CSI-2 camera connector, a USB On-The-Go (OTG) port, and an unpopulated footprint for a HAT-compatible 40-pin GPIO header. It is powered via a micro USB socket. Video output is via a mini HDMI port; composite video output can easily be made available via test points if needed. Sharing the same form factor as the original Raspberry Pi Zero, Raspberry Pi Zero 2 W fits inside most existing Raspberry Pi Zero cases.
SB Components launched "Serial Expansion HAT for Raspberry Pi " to expand the functionality and capabilities of the Raspberry Pi, This Expansion HAT for Raspberry Pi gives you an I2C interface & 2-channel UART with 8 programmable GPIO Pins. To do more things with this Raspberry Pi Serial Expansion HAT we added more slots and there are 8 programmable GPIO pins in which you can attach more accessories and Add-ons.