Romanesque Octagon Glass Door Knob (Polished Brass Finish) - the glass knob measures 2 3/8 inches in diameter and it has a projection of 2 1/8 inches. Solid brass rosette plates screws directly into the door with four wood screws and measures 3 1/4 inches in diameter. Is available in Polished Brass, Antique Brass, and Oil Rubbed Bronze. The dummy door knob is a fixed knob with double rosettes and is commonly used on French-style or bi-fold doors. This style is available as a single sided dummy knob (1 fixed knob), double sided dummy knob (2 fixed knobs), functional passage (non-locking) and functional privacy (locking) sets. Functional door knobs come with a standard 2 3/8 inch back set latch, or you can request a 2 3/4 inch back set at no extra charge.