... ) Keeps good condition without damage 2) Fire resistant, waterproof 3) Voltage withstand 4kv 1min under water CE,ISO 9001 INSULATION PIERCING ... : 1) Piercing connector, simple installation, no need to strip the cable coat 2) Moment nut, piercing pressure is constant, keeps good ... ) and CU(Al) or Cu and Al Elctrical Piercing Connector-Low Voltage