3M™ Cold Shrink Insulator WF Series is UL listed for direct bury and submersible applications in fresh or salt water environments for cable rated up to 2000 volts. The thick wall, open-ended, tubular, rubber sleeves are factory expanded and assembled onto a removable core. The core is removed after the tube has been positioned 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.