Magma Dual Horizontal Round Rail Mount - 7/8" or 1". 5mm) These incredibly strong rail mounts have a unique pivoting design which allows them to mount to straight or curved rail or across the corner of a stern rail. Made of 18-8 stainless steel and 356 anodized aluminum they instantly detach without tools for compact storage. Specifications for Magma Dual Horizontal Round Rail Mount: Manufacturer: Magma Color: Black Package Contents: Magma Dual Horizontal Round Rail Mount Magma T10-580: Dual Horizontal Round Rail Mount - 7/8" or 1"