Constructed of Powder-Coated Marine-Grade Aluminum and Stainless Steel Hardware. The mount has been Salt Spray Tested and UV Tested for thousands of hours (including stainless steel bolts and springs) to resist high salt water and UV corrosion. Cast in one piece of aluminum rather than screwed together, it remains strong and durable even under the impact of waves. The 1.5 inches double ball mount is a heavy duty multi-angle drill base pedestal mounting solution for tablets, cell phones, fish finder and more. It is designed to install directly on a table, cart, desk, in a vehicle, boat, or on any flat surface (complimentary 316 marine grade stainless steel screws).