Magma Single Side Bulkhead Square/Flat Rail Mount - This all 18-8 stainless steel mount attaches to any vertical flat surface such as bulkheads, hulls, transoms or cabin sides. Also mounts to square and flat rails. Fits horizontal rails up to 2-1/4in (57 mm) high by any depth or vertical rails up to 1-5/8in (41 mm) wide by any depth. Some fasteners required for installation.