Magma Horizontal Round Rail Mount 1-1/8" or 1-1/4" HD Dual. Normally two rail mounts are required to support the mast and one must be used at the top and one at the bottom to secure the rail mount. This Dual Horizontal Round Rail Mount does not allow this to happen. Instead the mount positions the horizontal rail mounts to provide secure support by using leverage similar to the way a traditional fixed post mount does. However they are specifically designed to work with round rails that are a little bigger than a normal post such as those found on pontoon and sterngate boats as well as with the ball-jointed edge of a square rail. This flexibility allows you to secure your rail support at the top and bottom of your boat. The Dual Rail Mounts are incredibly strong rigid and will not slip on the rail. Made of 18-8 stainless steel and 356 hard anodized aluminum they instantly detach without tools for compact storage leaving no hardware on the rail. Specifications for Magma Dual Horizontal Round Rail Mount 1-1/8" or 1-1/4" HD: Manufacturer: Magma Color: Black Package Contents: Magma Dual Horizontal Round Rail Mount 1-1/8" or 1-1/4" HD Magma T10-585: Horizontal Round Rail Mount 1-1/8" or 1-1/4" HD Dual