Uplink Port Design - 16x PoE ports plus 2x gigabit ethernet ports and 1x sfp optic port. Extra uplink port design enable all PoE ports be used for PoE power devices. Rack Mountable - Durable metal housing, built-in standard DC48V power supply. Desktop or 19 inch Rackmount (via included extensions). Extension of Power and Data - The extend mode increases the maximum transmission distance from 100 meters to 250 meters. You may choose ON/OFF mode based on your specific needs. PD Detection - Ports automatically detect devices, power detection (PD) function ensure only devices require PoE receive power and will not burn your device. LED Indicators - Various LED display functions can real-timely display the device's current working conditions, and help prompt facility and remove trouble easily. Yellow for power and green for activity.