This is an exciting electronic learning toy. Elenco's new Snap Circuits makes learning electronics easy and fun! Just follow the colorful pictures in our manual and build exciting projects such as FM radios, digital voice recorders, AM radios, burglar alarms, doorbells and much more! You can even play electronic games with your friends. All parts are mounted on plastic modules and snap together with ease. Enjoy hours of educational fun while learning about electronics. No tools required. Uses "AA" batteries. The Snap Circuits Extreme Version contains over 80 parts to build over 750 experiments and includes a PC computer interface. Includes everything from SC-500 plus experiments in solar, electromagnetism, vibration switches, and 70 computer interfaced experiments. Requires 4 "AA" Batteries. WARNING: CHOKING HAZARD - Small parts. Not for children under 3 yrs.