Clutch type hook allows sliding timber door to be slammed and locked shut without the use of the key. Hookbolt can be released by handle or key from one or both sides of the door, and can be deadlocked by one full turn of the key towards the forend. A projecting stump on the forend engages into the locking plate to prevent the door being lifted when in the closed position. This item previously branded Chubb Locks.