This mount is specifically designed for use on vertical surfaces.  It has an attractive black molded body that looks great on any vehicle.  When installed, the coax connectors are concealed on the inside of the vehicle (requires one 13/32" (10mm) and one 13/64" (5mm) mounting hole).  This mount may be used with single or dual installations.  The actual mounting surface is approximately 3.125" (79mm) x 1.675" (43mm).  Outward protrusion is about 1.875" (48mm).  This mount comes complete with all of the required mounting hardware, rubber gasket, metal reinforcement plate, nylon insulator and ground terminal lug.  The M-2 can be mounted to surfaces up to 0.28" (7mm) thick.  If using a spring with a base diameter larger than 0.700", a split lock washer is required between the mount and the spring to ensure proper seating of the spring to the mount surface.