Material: Bulk molding compound, unsaturaced polyester. Nut inserts: Brass, various specifications are available. ...... High Voltage InsulatorDrum Bus BarHexagonal Bus BarOctagon Bus BarBus Bar SupportsHigh Voltage InsulatorMaterial: Bulk molding compound, unsaturaced polyester. Nut inserts: Brass, various specifications are available. Test specifications: JIS C3801 and JIS C3851. Color: Dark ...