Vintage-style Hardware High quality & well-built internal mechanism for sturdy operation Traditional & common size interior mortise lock for doors Thumb turn operation for bolt 2-1/2" backset Solid brass plates, thumbturn piece, latch, & throw-bolt Thick steel casing with black japanned finish Reversible for right or left applications Doorknob spindle hub:  9/32" (7 mm) Set includes a mortise strike, a solid brass thumb-turn, & four flat head screws For an emergency release key for the outside,  see here. Product Description Specs A traditional & authentic old-style interior mortise lock set with a thumbturn for the deadbolt operation & locking of doors. This lock is a replica of common-style mortise locks from the past century, although it will easily fit in with any time period from early 20th century to current modern styles. The plates, thumb turn piece, latch & throw-bolt are made of high quality solid brass for a real handsome look. The lockset case is made of thick steel with a well-built internal mechanism & bolt, unlike many basic locks out on the market today. The 2-1/2" backset measures from the edge (front) of the plate, to the center of the hole. This old-style privacy lockset is available in unlacquered brass (will patina naturally), oil rubbed bronze, & polished nickel finishes. Beautify & secure your doors with this handsome & classic piece of hardware. For an emergency release key for the outside,  see here.      Hardwick & Sons is pleased to offer vintage-style hardware for the many people who desire to fashion their homes with charm, quality, & style. The traditional-style hardware that we showcase are true & faithful reproductions of classic hardware pieces found in the many homes from across America throughout the past century. Product Backset Case Size Face Plate Keyhole to Knob Hub Screw Hole Spacing Square Hole Size for Thumbturn Piece Strike Plate  Size Model # Interior Mortise Lock 2-1/2" 3-1/8" High   x   3-5/8" Wide   x   9/16" Thick 5-1/4" High   x   15/16" Wide 2-1/4" 4-5/8" 3/16" 3-7/8" Long x 1" Wide (8887) BMH8919X   For California Residents: WARNING: Cancer & Reproductive Harm - www.P65Warnings.ca.gov WARNING: Drilling, sawing, sanding or machining wood products can expose you to wood dust, a substance known to the State of California to cause cancer. Avoid inhaling wood dust or use a dust mask or other safeguards for personal protection. For more information go to www.P65Warnings.ca.gov/wood