This is a Power over Ethernet (PoE) mini expansion board for the 3B+/4B that supports the IEEE 802.3af networking standard. If you already have a PoE router or switch that supports the IEEE 802.3af network standard, this expansion board allows you to network and power your with just one cable. Suitable for 3B+/4B, can be used with the official case, does not take up more space Supports PoE Power over Ethernet, supports IEEE 802.3af PoE network standard. Fully isolated switched mode power supply (SMPS) Adopts more compact component layout, smaller overall size, more flexible use Color: As Shown Material: PCB PoE Power Input: 37V ~ 57V DC Input Power Output: 5V 2.5A DC output Network Standard: Supports IEEE 802.3af PoE. Package Contents: 1 x for 3B+/4B expansion board 1 x fan Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.