FPL's Pickfair patio sliding door lock set is made from solid brass and available in an array of popular finishes. This version is designed as a full replacement for the old California Classics sliding door locks, and replaces the original lock mechanism and trim. The included FPL 560 lock mechanism is the only compatible replacement option that fits the original California Classics door milling. Please see the 'Old Cal Classics Specs' photo to ensure that you have the old style lock set before ordering a replacement. The Ambassador patio sliding door lock set includes a European half cylinder with a thumb turn and the 560 mortise mechanism that is specifically designed to replace original California Classics sliding door hardware. The mechanism is retracted by the thumbturn on the inside. This Pickfair style is also available in the keyed (locks/unlocks with a key on the outside and a thumbturn on the inside) and double keyed (locks/unlocks with a key on the outside and on the inside) functions specifically for replacing original California Classics sliding door sets. It is also available in the dummy (used on the inactive door when two sliding doors meet in the middle) function. These items are listed separately. To open, press down on the lever to disengage mechanism from strike, then use the lever as a pull to slide your door open. When closed, locking the profile cylinder secures the door by keeping the lever from operating. Trim plate screw hole spacing: 7-11/16" center-to-center (c-t-c) Door thickness: 1-3/4" to 2-1/4" Plate width: 1-3/4" Plate length: 9-1/8" Projection from door face: 1-53/64" Backset: 50mm Lever to cylinder spacing: 59mm center-to-center (c-t-c) | Old California Classics checklist: 1" threaded round mortise cylinder, lever below cylinder, 3-1/2" cylinder to lever center-to-center (c-t-c), 8-1/4" mechanism front plate with receiver