Design to allow antenna wire to feed directly through the base eliminating the need for a separate cable grommet. Base is designed with a recess which, when filled with silicon sealant will make a water tight fitting. All stainless steel construction. Ideal for TV, Loran, GPS and VHF antennas with standard 1 inch - #14 threads. Dimensions: 4`` H x 2-7/8`` W x 2-1/8`` Diameter. Uses 1/4``FH Fasteners.