3M™ Cold Shrink Connector Insulators 8420 and 8430 Series are EPDM tubes designed using a unique Cold Shrink delivery system. Products are supplied pre-stretched on a removable core for efficiency and easy of installation. Removal of the core (unwind) after positioning allows the tube to shrink into position forming a moisture-tight seal. The live memory action of the specially formulated material ensures a permanent, durable environmental seal and insulation.