The brass knobs measure 2 1/4 inches in diameter. The Art Deco backplate measures 3 3/4 inches tall and 3 4/4 inches in wide. Screws directly into the wood door. 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. Single sided and double sided dummy options can be used with or without a borehole, if no borehole is present countersinking may be required. 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.