"The Scotty Ball Mount with Fish Finder and Universal Mounting Plate ensures easy mounting for any prized boating and fishing accessory. The bigger, 1-1/2"" ball design gives you a much greater clamping force for larger accessories while still having a smooth, full range of motion. The Scotty Ball Mount with Fish Finder and Universal Mounting Plate accepts large fish finders, for maximum support and versatility. Base mount: 2-1/4""L x 2-1/4""W. Mount: 6.5""H.Manufacturer model #: 0163. Marine electronics mount with Scotty quality and durability 1-1/2"" ball Greater clamping force for larger accessories Smooth, full range of motion Recommended for use with fish finders up to 9"""