Yale 89 Deadlocking Standard Nightlatch 60mm (D) Chrome is commonly used on front doors. The latch automatically deadlocks on closing the door also the snib function (bolt hold back button) enables the latch to be held back. Inside handle can be deadlocked by a reverse turn of the key in the outside cylinder after closing the door. Key operation from outside and lever handle on the inside. Snib function enables the latch to be held back.