Octagon Glass Door Knob With Ornate Backplate (Polished Chrome Finish) - the door knobs measure 2 3/8 inches in diameter and have a projection of 2 3/8 inches from the base of the glass door knobs to the edge of the glass door knobs. The ornate back plate screws directly into a wood door using four wood screws (included) and measures 10 inches tall by 2 7/8 inches wide. Single sided and double sided dummy options can be used with or without a borehole, if no borehole is present countersinking may be required. Available in Polished Brass, Antique Brass, Polished Chrome, and Oil Rubbed Bronze finishes in single dummy, double dummy, passage and locking privacy styles. 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. Constructed from solid brass and hand finished. Functional door knobs come with a standard 2 3/8 inch back set, or you can request a 2 3/4 inch back set at no extra charge.