POE HAT (B) for Raspberry Pi 4B/3B+,Power Over Ethernet HAT,Support 802.3af PoE Network,802.3af Power-Sourcing Equipment RequiredIntegrates PCF8574 IO expander for I2C bus, providing pin P0 for directly fan control, and more spare IO pins0.91Inch OLED, for monitoring processor temperature, IP address, and fan status in real-time; Onboard cooling fan, allows auto running on powerup OR programmable control, configured by switchPOE POWER INPUT:37V ~ 57V DC in. POE POWER OUTPUT:5V 2.5A DC out .OLED PIXELS:128x32. NETWORK STANDARD:802.3af PoE. OLED DRIVER:SSD1306. OLED DISPLAY COLOR:white.DESCRIPTIONPower Over Ethernet: Providing Both Network Connection And Power Supply For Your Raspberry Pi In One CableCooling Fan: Allows Auto Running On Powerup OR Programmable Control, Configured By Switch; Automatically Turn On/Off Depending On The Raspberry Pi Processor TemperatureOnboard PCF8574 Chip: PCF8574 IO Expander For I2C Bus, Providing 8 IO Pins, Of Which P0 For Fan Control; And Extra Spare Pins On Solder Pads (P1-P7, INT)PoE (Power Over Ethernet) capability,802.3af-compliantFully isolated switched-mode power supply (SMPS)colour: blueMaterial: PC board + metalsize: 65x56.5mmPackage Contents: 1*PoE HAT Expansion Board1*Screws kitOnly the above package content, other products are not included.Note: Light shooting 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.