CRL Designer Series "D" Shape Locking Ladder Pulls have a fully concealed deadbolt locking mechanism that locks into the floor. Simply turn a key or thumbturn located at a comfortable height above the finished floor to lock or unlock your doors. Supplied with our standard 7-pin Rim Cylinder with interchangeable core, that can be used as the final cylinder or as a temporary, and is easily replaced. If staying with the 7-pin format, just remove the core, have it re-keyed or replace it with a new one. If proprietary 6-pin Cylinders are required, simply remove the entire Rim Cylinder provided and replace with the proper Rim Cylinder of your choice. Ladder Pulls will accept most standard manufactured Rim type cylinders.