3M's Cold Shrink Connector Insulators 8420 Series are designed to provide a reliable and water-resistant seal for electrical connections. These open-ended, tubular rubber sleeves are factory expanded and assembled onto a removable core. After positioning, the core is removed, allowing the tube to shrink and form a tight seal. Ideal for primary electrical insulation, splicing, and physical protection, these insulators are suitable for both indoor and outdoor applications, including direct burial and submersible environments. Their robust rubber formulation withstands backfilling and resists acids, alkalis, and ozone, ensuring long-lasting performance.