20Pcs Worm Gears, 8x2x4.5mm/0.31×0.08×0.18′(ODxIDxT)142A 0.5Modulus Plastic Gear, White High Rotating Speed Wide Uses for Pulley Belt Shaft Robot RC Motor Worm Crown Hand DIY Car Kit

About This Product :

• Outer Diameter:8mm;Shaft Diameter : 2mm.Most gear is 2mm aperture (tight or loose).
• The Gear Package included: spindle, single/double crown gear, pulley, rack, bevel gear, copper gear, bushings, axles, tires, rubber bands and so on, more accessories that you need for diy robots/motors.
• Multi-uses,Great for diy science and small production, product design and mechanical model.
• It includes worm gears,crown gears and a couple of other gears, suitable for DIY model production technology.
• This is the most complete gear set. It can meet your DIY needs.