Available at http://www.makershed.com The Gakken EX-System is a series of educational electronics kits produced by Gakken in the late 1970s. The kits use denshi blocks (also known as electronic blocks) to allow electronics experiments to be performed easily and safely. Over 25 years after its original release, one of the main kits from the series was reissued in Japan in 2002 and now you can get it here! Instruction Manual Included is in Japanese. English PDF Instructions available. Less