Bondtech BMG Integrated Drive Gear Assembly (IDGA) This Integrated Drive Gear Assembly Set is compatible with: All Bondtech BMG series extruders; All Bondtech upgrade kits for Prusa i3; All Bondtech upgrade kits for Prusa Mini; All Bondtech DDX Direct Drive eXtruders for Creality; BMG-HT for Funmat HT; Other BMG type extruders using the original Bondtech main shaft assembly and primary drive gears… … for instance the Voron ClockWork 1,CW1. It must be used with 3x8x3.0 mm ball bearings (INCLUDED). This IDGA, Integrated Drive Gear Assembly, replaces the following mini drive train items: Main shaft; Main gear; Set screw; Primary drive gear. Secondary drive gear, secondary shaft and secondary needle bearings ARE NOT SUPPLIED. Technical Specification Shaft length: 27.6 +/-0.08mm Shaft length to support ball bearings : < 3.3mm - 3.3mm > Filament teeth’s center to end of shaft : < 21.84mm - 6.30mm > Number of drive gear teeth : 17 Drive gear teeth length : 4mm Integrated drive gear Material: Hardened SteelMaterials Compatibility: Flexible : yes; Rigid : yes; Abrasive : yes. Number of main gear teeth : 50 Main gear teeth length : 3mm