A Security Lock for Doorknobs! Highly Innovative and Very Secured! As you know, door knobs have keyholes that can easily be pricked by a burglar. This is where KNOBLOCK comes in.A security cap is placed on the doorknob of the door.Then, it is fully secured by a security padlock which is inserted on the cap . You then lock the padlock with keys. The keys cannot be duplicated. Ideal also for travelling. Secures your things in your hotel room! Very practical and useful for thsi trying times.