Reely Steel Pinion Gear 21 Tooth with Grubscrew 0.5M

Reely Steel Pinion Gears - Module 0.5 - Reely 213985, A 21-tooth, module 0.5 steel pinion gear that is secured to the shaft by an M3 grub screw. Reely Steel Pinion Gear 21 Tooth with Grubscrew 0.5M

Price: 3.56 from Rapid Online Rapid Electronics Ltd.