10pcs 2mm Optical Axis Smart Robot Car Toys Plastic Accessories For DIY Model

Features: Best used for optical axis, car axle whose optical axis is 2mm Application: Gearbox, Capstan, Deceleration pattern in bar Specifications: Material: Plastic Size: 6*8mm (type#1); 6*6mm (type #2) Optional Modulus: 0.5 Package included: 10 x Gear