Surplus leftovers at antenna factory. Threaded 1"-14 marine antenna ferrule or 3/4" tube holder. Make your own antenna, these parts are gret for the DIYer. Or for anything you want to hold on a marine antenna mount. It has 4 cross holes around the diameter every 90 degrees for set screws (not included), or long screws of your choice. Flag holder? Rod holder? Whatever is under 0.774" will fit in the center. Precision machined from solid aluminum. Its 1.21" OD and the 0.77" hole at one end and the 1"-14 theads on other end 1" long. Total length is 3.43" and side hole for cable exit is .38" Weight of 1 is 3.3 oz.