The Polaris SP600S Set Screw Plug is a replacement part that take the place of the secure removable plugs present in the ISPB600 line of Polaris pre-insulated connectors. This plug fits connectors sized for 600 MCM - 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.