The 3M PST Cold Shrink Connector Insulators are factory-expanded EPDM rubber sleeves designed to provide waterproof seals for inline connections up to 1000 volts, with various diameter sizes available. They require no additional heat for installation, ensuring easy application in various conditions, including indoors, outdoors, and underwater. The insulators exhibit excellent durability and resistance to moisture, chemicals, and environmental factors, meeting multiple safety and performance standards.