3M Cold Shrink Connector Insulators 8420 Series are open-ended, tubular, rubber sleeves which are factory expanded and assembled onto a removable core. The core is removed after the tube has been positioned for installation over an inline connection, terminal lug, etc., allowing the tube to shrink and form a water-resistant seal. The insulating tube is made of EPDM rubber which does not contain chlorides or sulfur. Six diameter sizes will cover a range of cable up to 1000 volts for copper and aluminum conductors from 10 AWG through 1000 kcmil. To extend the useful life of this product in applications which are continuously exposed to high levels of ultra-violet radiation, overwrap with Scotch Super 33+ Vinyl Electrical Tape or Scotch Self-Fusing Silicone Rubber Electrical Tape 70.