Sea Dog 329510-1 Fixed Antenna Base<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Investment cast 316 stainless</li><li>Designed to allow antenna wire to feed directly through the base eliminating the need for a separate cable grommet</li><li>Base is designed with a recess which， when filled with silicon sealant will make a watertight fitting</li><li>2-7/8" diameter</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41NQi%2BGLReL.jpg" noproxy>