Explore how a magnet sets off this cool intruder alarm. It’s a fun project for exploring how a magnetic switch works in an electric circuit. Base, cover, magnet, magnet holder, eyelet plates, battery cover, adhesive tape, metal disc, terminal caps, screws, washer screws and detailed instructions. Required but not included in this kit: 2 x 1.5AAA batteries and a small crosshead screw driver.