Prevent damage from ozone, acids and alkalis with the 3M Cold Shrink Connector Insulator 8420 series. This black insulator works as primary electrical insulation for applications that are rated 1 kV. The open-ended, tube-shaped sleeve is made from rugged, EPDM rubber to repel moisture. Count on it to operate well within a temperature range of -40 to 194 degrees F (-40 to 90 degrees C).