The Zero Stem is a PCB shim that turns a Raspberry Pi Zero into a USB dongle. Once the shim is installed, your Raspberry Pi can be plugged directly into a computer or USB hub without any additional cables or power supplies.
The Zero Stem is compatible with the Raspberry Pi Zero v1.3 and the Raspberry Pi Zero W v1.1.
It is not compatible with the Raspberry Pi Zero v1.2 or any full-size Raspberry Pi.