Die Cast Zinc Insulated Conduit Nipple 1-1/4″, NPSM Threads
https://dev.nsiindustries.com/product/die-cast-zinc-insulated-conduit-nipple-1-1-4-npsm-threads/
The Bridgeport 1-1/4″ Die Cast Zinc Insulated Conduit Nipple serves as a short raceway between enclosures or boxes when used with a locknut. Conduit nipples are used to extend a conduit system. This nipple features NPSM threads.