Shop name:Chong Qing Shuo Yue Ke Ji You Xian Gong Si POE HAT (B) for 4B/3B+, Over Ethernet HAT,Support 802.3af PoE Network,802.3af -Sourcing Equipment Required Integrates PCF8574 IO expander for I2C bus, providing pin P0 for directly fan control, and more spare IO pins 0.91Inch OLED, for monitoring processor temperature, IP address, and fan status in real-time; Onboard cooling fan, allows auto running on OR programmable control, configured by switch POE INPUT:37V ~ 57V DC in. POE OUTPUT:5V 2.5A DC out . OLED PIXELS:128x32. NETWORK STANDARD:802.3af PoE. OLED DRIVER:. OLED DISPLAY COLOR:white. DESCRIPTION Over Ethernet: Providing Both Network Connection And Supply For Your In One Cable Cooling Fan: Allows Auto Running On OR Programmable Control, Configured By Switch; Automatically Turn On/Off Depending On The Processor Temperature Onboard 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 ( Over Ethernet) capability,802.3af-compliant Fully isolated switched-mode supply (SMPS) colour: blue Material: PC board + metal size: 65x56.5mm Package Contents: 1*PoE HAT Expansion Board 1*Screws kit Only the above package content, other products are not included. Note: Light 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.