Clare-Bell Brass set of 2 Threaded Door Knobs & Plates – insert in pre drilled hole and screw together for a traditional and elegant look. Designed for the 1:12 scale miniature setting in highly polished brass. Measures: 3/8 in wide x 9/16 in projection through door and including both door knobs. Screw together knob instructions: Drill 1/8″ diameter hole in door to install doorknobs. Hint: Lay the door flat on a scrap piece of wood when you drill the hole. The exit point of the drill will not splinter the back of the door. Hint: A touch of brown or black paint, magic marker, or crayon just under the key hole will add a realistic touch to your project.