Material: Polycarbonate(PC)+Engineering Plastics(ABS),freidly insulation materials,electrical and fire safety. Construction: 1.Sides get thick,enhanced gradually from top to bottom,and improving sides strength and reliablity. 2.Doubel layers are applied to the joint of cover and sides 3.The indent bottom right angel is easy to be folded.While connecting with the veritical duct by cutting two end to form straight,flat outlets,fully protect the cable. 4.The floor is with rails,allowing to add traps to tighten wires and make it organized,neat and save space.