4M Science Museum Top Secret Intruder Alarm</br></br>Product Description</br></br>Construct your own intruder detector buzzer for your bedroom door and learn about connecting electric circuits in the process! Each kit contains a plastic platform and accessories?? metal pegs?? an electric buzzer?? electric wire and string for the alarm tr</br><br/>http://www.amazon.com/gp/product/B000FCM0B0