KEYHOLE BLOCKER for mortice Sashlock or Deadlock LOCK BLOCK
This genius device is called the Lock Block and is used to block anyone from entering a key into your lock. Very handy if you are sharing a house with others and want to be sure no one enters your room with a key while you're not home.Simply enter the Lock Block into the keyhole and turn the key of the Lock Block. Pull the key out of the Lock Block and the device will stay in place within the keyhole. Please note that these will fit 95% of all Mortice locks. The do NOT work in cylinder locks .