"I bought this as a direct replacement for an older model, but hey, they have changed a lot of dimensions, including the screw pitch that fits the lock, but only by a couple of millimetres. What a pain to fit, and also the pattern of the screws on the striker box has been changed. Why? The older model failed because the aluminium bit that rotates with the key was so soft it wore away after about ten years and so the bolt would not reliably withdraw. I discovered this fault after purchasing the new one, or I probably would have bought a better make. Also the keys on the illustration seem to be brass, like the older model, but hey-Ho they turned out to be cheap steel chromed."