Shakespeare 4722 Nylon Rail Mount 7/8 - 1" Rail
This sturdy plastic mount attaches to 7/8in and 1in horizontal rails and has a side slot in the 1in-14 thread section for antennas with coax exiting the bottom center of their ferrule.
Standard 1in-14 thread.(male)
***This product is ON SALE (reduced by 5%) until 11/16/2018***