The product replaced a Chubb lock and that was fine. I had some problems with the action of the latch that is the latch when drawn back would not come out again. After speaking to the supplier a lubricated the lock and the latch now works fine. The advise was to squirt some oil into any aperture of the lock and leave for a while which I am not sure would have worked. I took the lock apart and used graphite dust lubricant which worked fine. I think that the lock should have worked without the customers extra work