Nightlatches

deal for use on a front door, these locks come with a latch which can be opened from the outside with the key, then at night if the snib is pushed up the latch is locked in position and cannot be unlocked with the key. The Snib can also be used to lock the night latch in the open position, handy if you're popping back in and out to bring the grocery shopping in from the car! However to ensure the security of your property, you should always make sure to release the snib once you're done, allowing the door to lock once again.