NMO mount to UHF Female adapter. Useful for mobile applications where you want to plug a PL-259 or UHF Male onto the bottom of the mount. Many uses in making base station antennas and connections as well. The thread is 1" in length end to end. The NMO ring is about 1/4" thick so that leaves about 3/4" to pass through the mount material and connect up a UHF Male. You will have about 3/8" of available thickness for the mounting material if using a PL-259. Comes with the o-ring and a heavy duty nut and washer. The RF pin is gold plated.