Another in the "Science for Adults" series from Gakken, this vacuum engine is touted as "a real external combustion engine kit using a vacuum, with an external heat source." Now, by "a vacuum," they don't mean an Electrolux or a Hoover; they're talking about "a space entirely devoid of matter." This kit includes all the parts you need to create a vacuum engined car. The engine itself is easily removable, and assembly takes about two hours (no special tools required), according to the packaging. The multi-media kit features nice die-cast aluminum parts, rubber tires, and more. Instructions included (all text in Japanese).