This image shows two mortise cylinder locks, each with its own key attached—one using a Kwikset-style key and the other a Schlage-style key. Rekeying these cylinders allows property owners to match new or existing locks to a preferred key system. This is commonly done during lock replacements, access resets, or when consolidating multiple locks to work with a single key type. Mortise locks are frequently used in both residential and commercial entry doors.