When is a door chime not a door chime? When it’s a knock.

Check out the Knock-Knock Door Chime, a device that doesn’t show itself off as itself. You install it on the inside of your front door, on an adjoining wall, or up to 100 feet away, and let the chime do the rest. When a friend or neighbor or door-to-door salesman knocks on the front door, the chime sounds inside the house, alerting you to the presence of someone you do or do not want to see. No wires are needed, and you can pick one up for $49.99 USD.