The connection of Charging protection ground wire is to provide safety protection measures for electronic power equipment to protect the safety of equipment. Fiber optic transceiver: 8 100m standard Poe power supply ports: 1236 transmits power and network (connected to cameras, network equipment, etc.) 1 100m SC optical fiber port: can transmit 20km Colour:black Material:Aluminum alloy Size:202 x 140 x 45mm Package Contents: 1x Network Switch Only the above package content, other products are not included. Note: Light 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.