If your door knob set is acting up or broken, this E 28318 Mortise style fluted glass door knob set is the perfect choice for updating and fixing hardware on interior doors. With a beautiful and classic fluted glass and matte black finish, it's the perfect choice for your antique or vintage interior doors. Installation is a breeze, and the glass door knob set features 2 in. outside diameter knobs. These door knobs are for interior use only, and includes a 17/64 in. x 3-1/2 in. steel spindle with 3/8 in. -20 threads. This classic style door knob set fits square drive spindle systems commonly found in antique and vintage door hardware sets, and it can adjust to accommodate different door thicknesses. The diecast base on these knobs include the set screws for fastening the knobs to the square spindle, but it does NOT include any of the following components and they must be purchased separately: The internal mortise lock body, the door rosettes, the trim and strike plates, or the latch and fasteners. Note: This item cannot be used on pre-bored doors that have large, newer style door knob holes without first prepping them to receive this hardware. Installation tip: Apply a small amount of Loctite Thread Locker 271 to the set screw threads in the event they are loosening - Loctite purchased separately.