Union High Security Night Latches. Lockable handle prevents someone reaching in and opening the door. On closing the door, Latchbolt automatically deadlocks. The bolt is withdrawn by handle inside and key outside unless handle is locked by key. Complete with fixings and cylinder. Designed for applications requiring an internal locking handle. Concealed fixing. Also suitable for steel and composite doors - special fixings required. When the handle is locked whilst in rotated position, the bolt is held withdrawn. The bolt may be held in the locked or in the withdrawn position by operating the snib. When door is closed bolt is automatically locked against end pressure by the anti-thrust slide. Case & Keep: Zinc. Handle: Zinc, finished to match case and keep material. Outside Cylinder: Brass, 5 pin tumbler mechanism. Inside Cylinder: Brass, 3 pin tumbler mechanism.