This is a motorized Japanese designed construction kit that lets you build moving machines such as cars, boats and robots. Features of the set include clear plastic capsules that snap together, capsules containing motors, gears, switches, and axles, and parts like wheels, propellers, and pontoons. It is possible to build land vehicles or floating water models including tricycle, bicycle, windmill, fire truck, tank, tractor, racing car, robot car, helicopter, propeller ship, crane, belt conveyor, and tunnel excavator.
Set was developed by the Mitsubishi Pencil Company in the 1970's. It was ranked in the top 100 games of 1980 and 1981 by Games Magazine. The toy line Capsela was popular worldwide in the late 1970s and early 1980s and was considered an early STEM educational toy.
I purchased the set in 1979 during a business trip to Japan. The set is complete including manuals. Note the box shows wear on the edges. ChatGPT can give you detailed information about this set.