The Yale Y3 nightlatch is a high security nightlatch which can be used as an additional lock on primary doors. Latch bolt automatically locks when door is closed and is suitable for left and right hand inward opening doors. It features a snib button which can be used to hold open latch bolt or to deadlock door when in the closed position. Supplied with a Satin Nickel rim cylinder to operate the nightlatch from the outside.