The Polaris SP-350-ISPB Watertight Set Screw Plug is a replacement part that takes the place of the secure removable plugs present in ISPB Polaris pre-insulated connectors. This plug fits connectors designed for direct burial or temporary submersion and sized for 350 MCM to 12 AWG wires, covering the set screws used to tighten their connections. Protect the interior of your Polaris pre-insulated connectors, each port of which is pre-loaded with an oxide inhibitor to ensure a low-contact resistance connection, by guarding the set screws from outside contaminants. Polaris designs connectors for use in a wide range of splicing applications, including installation in cable trays, panel boards, ducts, raceways or troughs.