This is the 22 Tooth Optional Steel Pinion Gear for 5mm shaft CNC Steel Gear then Nitriding to increased wear resistance, improved fatigue life, and enhanced corrosion resistan Blue Aluminum base construction One pinion gear One set screw 4x4mm 2mm hex wrench to install the set screw Teeth count: 22 teeth Teeth pitch: 32 pitch width: 9.7mm (0.38") Inner diameter: 5.2mm (0.20") This gear is designed for 5mm or 1/8 shaft with 5mm to 1/8 conversion Sleeve