These double cylinder, heavy-duty entrance mortise locksets are constructed of various materials and come in a polished brass finish. They are designed for use on exterior entry doors, engineered to match the vintage hardware of interior doors, without jeopardizing the security of your home. For use on entry doors ranging from 1-3/8 inch to 1-3/4 inch thick, and with the Segal keyway lock cylinders you can enjoy the beauty of yesterday’s vintage hardware with the strength of modern day security hardware. The knobs of these locksets are constructed of diecast and reinforced steel components, and they’re finished off with a beautiful wrought, solid, polished brass finish. A gray plastic dust box is also included for installation beneath the strike plate. As an increased security feature, this lockset features a split spindle knob system designed to prevent breaching of hardware from the exterior side of the door. The spindle half with the female threading and cross pin inserts from the exterior, while the spindle half with the male threading inserts from the interior side of the door. The knobs fasten to the spindle pieces with the set screws found on each knob shaft. Although the handing's of these locksets are reversible (instructions included), there are matching locksets available with opposite handed latches ready for installation. Detailed, simple to follow installation instructions are included with each entrance mortise lockset.