This Basic kit is compatible with DDB extruder DIY and other the same type extruder, about the printed parts file, you can download it at Thingiverse Forume
Dual Drive gears is made from Hardened steel material with high precision, and nickel plating, while Pinion Gear is made from brass material.; for the Black ( or White) shaft gear, which is injected with stainless steel rod, it is stable
Package: 1 Set direct drive Basic kit (Not including printed parts)
For the big shaft gear, it may come with white or Black color, please know before ordering.