3M Scotchlok Insulation Displacement Connector 558 electrically connects a tap wire to a run (through) wire while insulating the connection. The connector is polypropylene insulated and self stripping.3M Scotchlok Insulation Displacement Connector 558 is suitable for control circuit wiring, fixture wiring, appliance wiring, signal and PA systems and automotive/boat/RV wiring. It is 600V rated for building wire and 1000V rated for signs, fixtures and luminaires. The connector withstands temperatures of 221 degrees F (105 degrees C). UL Listed, CSA Certified and RoHS 2011/65/EU Compliant.