This special device was custom-made by the production for use by Christopher Lloyd as "Dr. Emmett Brown". This is the Sleep-Inducing Alpha-Rhythm Generator that Doc uses to put Jennifer to sleep when they arrive in 2015, he also uses it on Marty Jr., but that scene was not seen in the final cut of the film. The prop is constructed of resin with the ability to open by pressing a button on the top of the device. The lights are powered by a battery that is hidden within the resin handle and no longer has a charge to power the lights. This exact prop is also featured in the Hollywood SFX museum prop book from Japan. It is believed that there are only two of these in existence and this is the only one that had the hidden battery for use during filming. For this item, our ScreenUsed COA is co-signed by Bob Gale, producer and writer of the movie.