Mego corp started to import Micronauts in 1977. The Microman concept was a simple one, they used a 5mm peg and hole. This allowed any item from the line, whether it be figure or vehicle or playset, to be fully interchangeable with each other and assembled any way the child wanted.
Micronauts went on strong until about 1979, when Mego finally went out of business in about 1980. In that 1979-80 retail year, the Micronauts saw their first original characters not to be based on the original Microman line