75 Type Plastic Crown Gear Single Double Reduction Gear Worm Gear Description: Material: plastic Type: spindle gear, crown gear, single gear, double gear, worn gear, bevel gear, belt pulley, belt, connecting rack, axle sleeve, tee collar Quantity: 75 Feature: 75 type ideal for DIY science and small production, product design and mechanical model Package included: 19X Double Reduction Gear(each one) 12X Single Reduction Gear(each on) 11X Crow Gear(each one) 2x Worm Gear(each one) 9X Spindle Gear(each one) 7X Belt Pulley(each one) 6X Axle Sleeve(each one) 5X Belt(each one) 2X Connection Rack(each one) 1X Tee Collar