Description: Materials: Stainless Steel Screw Hole Diameter: 2.4cm/ 0.94inch (Outer); 1.8cm/ 0.7inch (Inner) Base Size: 9.1 x 6.3cm/ 3.6 x 2.5inch (L x W) Base Screw Hole Diameter: 0.7CM/ 0.3inch Distance Between Base Hole Center: 7.4cm x 4.6cm/ 2.9 x 1.8inch Dual swiveling ratchet design Fits all standard 1" marine antennas Heavy duty construction for tough conditions Package Includes: 1 Piece Boat Antenna Base