Aoyagi Metals Industry Co. Ltd (青柳金属工業有限会社 Aoyagi Kinzoku Kōgyō Yūgen-gaisha) (commonly known as Ayk in America and Aoyagi in Japan) was a Japanese company that became notable in the 1980s for its radio-controlled cars. Conventional manufacturers mounted their differential gears between the right rear wheel and the motor compartment, but ayk placed theirs within the axle, which centered the weight more proportionately and kept the differential gears protected. By 1984, they resorted to an outboard gear diff much like the current Delta of the time.