Suitable for heavy duty use in industrial and commercial buildings, institutions, clubs, schools, hospitals, hotels, and similar buildings. 3570 Series Cylinder Mortice Locks are made from quality materials to meet high durability and strength requirements. These locks have various latching functions which can be operated by key or handle outside and by turnknob, key or handle inside. For ease of selection specify primary lock (3572SC). This lock can then be easily adapted to suit function required. These locks have various latching functions which can be operated by key or by handle inside.