1875 Two-Point Deadlock provides security for roll-up doors, security screens, or similar doors. Two-point locking is achieved using two bolts, which are operational from either or both sides of the deadlock. Function: For overhead doors, roll-up security screens, or similar doors. Provides turn operation of two bolts from either or both sides. Accepts standard mortise cylinders for key control of bolts to secure them in either projected or retracted position. Operation: 90° rotation of turn projects or retracts bolts. 360° turn of key deadlocks mechanism, preventing operation of the turn in either locked or unlocked position. Lock accepts any standard 1" [25.4 mm] length, 1-5/32" [29.4 mm] diameter mortise cylinder with MS® cam such as the 4036 Mortise Cylinder or thumbturn such as the 4066 Thumbturn, available separately. Lock accepts cylinder from either or both sides. This listing: part 1875-IB-603 (ZINC).