This adaptor is made from high quality chrome plated brass and has one internal 1” – 14 TPI thread and one external 1.25” – 11 TPI thread. The adaptor can be used for installations where the cable has to be accessed from the side. The external thread fits the N240F revolving nut which is supplied with many of the AC Antennas products. The adaptor can also be used to convert from one thread to the other.