Rim Cylinder

Rim Cylinders are used in dead bolts that are mounted with screws from the opposite side of the door.
Most commonly on garage doors and flush / surface mounted deadbolt locks
Commercial door Panic devices also use rim cylinders
The length of the tail piece varies and most have break away marks at 1/4" increments
Rim cylinders are available in many keyways including Schlage, Kwikset, Yale and others.
The Cylinders listed are generic, not original Schlage, Weiser, Kwikset, etc. unless specified as such