Spec Sheet Preview: Model OH601S Surface Backbox Shown Right The Alpha Communications® models OH600S and OH601S are surface mounting backboxes. They are both made of steel, painted in a Black powder coat epoxy painted finish for durability. They are among our most popular surface mounting boxes, and are used with a variety of intercom entry lobby panels, and remote intercom stations, to allow they to be surface mounted on the finish of a wall. Typically, wire access is from the large opening in the rear of each box, b …