Style 4187-HD is an extra heavy duty stainless steel ratchet mount for use on high speed boats, with big antennas and tough conditions.Versatile four-way ratchet design for deck or side mounting on slanted or level surfaces, in an extra heavy-duty stainless steel construction with extra strength and rigidity.The quick-action handle makes raising and lowering the antenna easy, and the ratchet makes it easy to return the antenna to its correct, upright position. Great for high-speed boating and other high-stress applications like hard tops, T-tops and radar arches.Key FeaturesBolt holes: 5/16" dia., 3" x 1-1/2" on centerSpecial 9/32" hole for cable feed-through eliminates removal of most factory-installed connectorsStandard 1"-14 thread.(male)Base Diameter: 4-1/8" x 2-1/4"Stainless steelSame as Style 4187 with extra strength and rigidityUse wherever its extra heavy-duty construction is needed