Features: The Power-over-Ethernet (POE) module provides a convenient and cost-effective way to deliver power to your device. The module allows you to put a for DC voltage on specific pairs of the Ethernet cable so that devices connected to the network can use it as a power source. The onboard cooling fan can automatically run under power or programmable control when the processor temperature is high. Its small size is a perfect match for the 4B and 3B + in IOT and building automation applications. It provides clean and reliable power for 4B / 3B +. for Protection Circuitry,Transient Overvoltage, Undervoltage Lockout, Thermal Shutdown, Foldback Current Limiting. Specifications: PoE power supply: 37V~57V for DC in Output: 5V + -5% to 2.5A * Network standard: 802.3af PoE Size: about 30x30mm / 1.18x1.18 inches Package Includes: 1Set x 4 Model B/3B+ POE network expansion board note: No retail package. Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!