This is the Empty Casket version of the Paranormal Music Box.  
It works just like the expensive version.  It uses a sensor to trigger a music box movement to play.  Use it in a hallway or doorway to warn you of a spirit entering.  
It runs off a single 9V battery, and lasts a long time.
 
The Music Box is made to order. Please allow 2-6 weeks before they are ready to ship. (2 weeks if I have all the parts on hand, up to 6 weeks if parts need to be ordered).