Mortise Cylinders are threaded into mortise locks, secured by a set screw through the edge of the lock.
Cylinders vary in length can be 7/8, 15/16, 1, 1-1/8, etc
The Tail piece on back of cylinders vary and come in several designs.
Adams Rite is most common on commercial doors
The Marks style is common on most Steel Security doors.
We stock the Marks orignal and aftermarket and an assortment of Adams-Rite style cylinders
Mortise cylinders are made of Brass or less expensive Zinc
The Cylinders listed are generic, not original Marks, Schlage, Weiser, Kwikset, etc unless specified as such