Lancaster Double Cylinder Mortise Handleset Trim Set Double Cylinder: A double cylinder lock is keyed on both sides of the door and is only locked and unlocked via a key. Often times they are used on doors where glass is near the door that could be easily broken and the thumbturn on a standard single cylinder lock would be accessible. Note: Some images of this product may be of single cylinder version of the lock with a thumbturn on the interior rather than a keyed cylinder. Caution: Double Cylinder locks can pose a safety hazzard in times of emergency due to requiring a key to unlock. Please check local codes before installing. The quality of style and show. Baldwin Estate Collection tells people that you live to a higher standard. While meticulously detailed for architectural accuracy, this is no hollow beauty. Select from many other products and accessories in the collection to coordinate your entire home and hardware decor package. Baldwin Estate is a component door hardware system and each component must be purchased separately for a complete package. Choosing the correct components for your particular application can be confusing and frustrating. Baldwin even offers an entire training course on this subject matter. Let our trained professionals choose the correct components based on your measurements and take the hassle out of this process! Below is a breakdown of components included with the product based on your configuration choices Included Items when configured as TRIM SET ONLY : Exterior and Interior Handleset Trim Knob(s) or Lever(s) Spindle NOTE: TRIM SET ONLY IS NOT A DUMMY SET. THE KNOB, LEVER, OR THUMBPIECE HAVE FUNCTIONALITY. TRIM SET ONLY IS SUGGESTED ONLY IF YOU ALREADY HAVE THE MORTISE HARDWARE! For a Dummy Set, Please see this model in the ".FD" version Additional items included when you select a DOOR THICKNESS : Mortise Lock (This depends on your door thickness and backset) Lock Cylinder(s) (Th