About this 3D model

Https://www.youtube.com/watch?v=UX6FOCJE__M&feature=youtu.be The same smallest key carrier with paradoxical gear, the wheels turn in the same direction. It is best to print in high quality. Thoroughly trim the sprockets, adjust the axles. NOP21 . It is best to print in high quality. Although deburring gears, adjusting axes. NOP21