The Polaris SP500 Set Screw Plug Is A Replacement Part That Take The Place Of The Secure Removable Plugs Present In Many Polaris Pre-Insulated Connectors. This Plug Fits Connectors Sized For 500 MCM 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 Connector