Fit for boat,sailboat yachts,car and trailer railings --Max. Screw hole size 6mm/0.23inch --All Boat Rail Fitting Size: 77*71*38 mm / 3*2.79*1.49 inches --Metal wall thickness 3mm/0.11 inch Package list : 2 x 30 Degree Round Base Hand Rail Fitting 6 x 304 Stainless Steel Screws