Lock-A-Liner, 1-1/2″, Polypropylene for Insulated Connectors
https://hotfix.nsiindustries.com/product/lock-a-liner-1-1-2-polypropylene-for-insulated-connectors/
The Bridgeport 1-1/2″ Polypropylene Lock-A-Liner liner lock converts ordinary bushings and connectors to code-approved insulating bushings and connectors.