PoE switch and Raspberry Pi 4 Model B sold separately. STANDARDS COMPLIANT POWER OVER ETHERNET SWITCH REQUIRED: The network switch or power sourcing equipment (PSE) must be compliant with the IEEE 802.3af or 802.3at PoE standard, particularly section 33.4.1 with regards to PSE electrical isolation of the leads.
https://www.amazon.com/LoveRPi-Power-Over-Ethernet-Raspberry-Compact-Non-Isolated/dp/B07WD7HXSQ

