UPDATE 2020-10-14: This is the new version with support for Raspberry Pi 4 natively.
The Aeotec Z-Stick gen5 is a self-powered Z-Wave USB dongle with push button for remote network creation (independent from external power and host microprocessor). When attached to a host processor, it becomes a Z-Wave communication device, which exposes the Zensys API (SerialAPI) through integrated USB.
This device is meant primarily to allow a host processor to control up to 232 Z-Wave devices using the Z-Wave technology protocol all the while simplifying Z-Wave network installation.
This is the new version, with white color and gen5 Z-wave chip!
Please note! There have been numerus reports of this stick not working with Raspberry Pi 4. However, this can work if you use a USB 2.0 hub between the Pi and the stick