The most popular types of tubular style locks are single cylinder and double cylinder.
A mortise style lock is the most secure form of an entry set.
A special cut in the door allows a longer and thicker mortise to slide into the pocket in the door itself,
providing superior protection.
Mortise locks are reliable and strong, thus offering good door security.
The classical appearance makes them more attractive than cylinder locks.
They're versatile, so you can use them with all kinds of door furniture and cylinders.