This is a video which will help you with an understanding of a night latch from R&M LOCKSMITH. A Night Latch is a lock which is used for convenience. Night latches has a handle on the inside and a rim cylinder on the outside which is used with a key. When inserting with a key the pins which sit inside the rim cylinder become flush or aligned. This allows the right key to be turned and simultaneously allows the tail piece to turn and the latch to draw back in to it’s mechanism. Nine times out of ten you vary rarely need to change the whole night latch. Only if it’s broken or worn then change the night latch. Advice: a rim cylinder with 2/3 keys will only be changed if: 1. You are locked out. 2. Forgotten your keys inside. 3. Lost your keys. 4. And sometimes when you have problems with your keys upon opening. Another advice – be careful when having cut keys, the key cutting shop may not have cut it properly. So check the keys straight away when at home or call R&M Locksmith.