The 3M Cold Shrink Connector Insulator 8420 series provides primary electrical insulation for your 1 kV-rated applications, and comes in a tubular, open-ended sleeve that protects from and resists acids, alkalis and ozone. The strong, EPDM rubber material helps the insulator do its job, even through extreme temperatures of -40 to 194 degrees F (-40 to 90 degrees C).