Adams Rite 4900-35-201-628 heavy duty deadlatch with backset of 1-1/8″. Left handed, mortised 2-5/8″ strike in flat standard jamb strike in clear anodized finish. Flexibility of traffic control and installation is offered by 4900 Heavy Duty Deadlatches. A reverse turn of the key while bolt is held retracted retains the bolt, to allow two-way traffic for applications which require free entrance at certain times and exit-only at other times. Interchangeable, without stile modification, with any MS1850A or MS1850S deadbolt of same backset and faceplate shape. Also retrofits to existing 4500 and 4700 Deadlatch preparations. 1-3/4” minimum door thickness required. Turn key or operate handle or paddle to retract spring-loaded latch bolt. To hold bolt retracted, push it in and secure by reverse turn of key. Uses any standard 1-5/32” mortise cylinder with MS® dimensioned cam. Bolt holdback, while bolt is held fully retracted, a reverse turn of the key retains the bolt, allowing the door to be free swinging. Latchbolt is 5/8” x 1” x 5/8” throw. Solid brass. Handing is easily reversible using only a screwdriver. Auxiliary latchpin is stainless steel. Deadlocks latch bolt to prevent “loiding” or case-knife entry. Faceplates measures 1” x 6-7/8”.