This is a over Ethernet (PoE) expansion board for 3B+/4B supports the IEEE 802.3af network standard. If you already have a PoE router or switch supports the IEEE 802.3af network standard, with this expansion board, you can the to the network and supply with just one network cable.Suitable for 3B+/4B, can be used with shell, does not take up more spaceSupport PoE over Ethernet, support IEEE 802.3af PoE network standardFully isolated switch mode supply (SMPS).Adopting a more compact component layout scheme, the overall volume is smaller and the is more flexiblePoE input: 37V ~57V DC input output: 5V 2.5A DC outputNetwork Standard: Support IEEE 802.3af PoEColour:blue + goldMaterial:PCB+MetalSize:65 x 32MMPackage Contents:1 x Poe HAT Expansion Board1 x HeatsinkOnly the above package content, other products are not included.Note: Light reflection and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.