What is this?Plastic Spindle Gear Set is a lightweight, durable transmission unit for precise power transfer in small systems. It links DC motors to driven components in RC cars, robotics, and DIY builds, ensuring reliable motion control with compact shaft alignment.What will I get? The plastic gears set,provides here,is in size of:Modulus: 0.5Material: PlasticOuter diameter:5mm/0.19 inch, 7mm/0.27 inch, 8.4mm/0.33 inch, 10mm/0.39 inchInner hole diameter:from 0.3mm/0.01 inch to 3.9mm/0.15 inchThickness:4.2mm/0.16 inch, 5mm/0.19 inch, 5.9mm/0.23 inch, 6.2mm/0.24 inch, 6mm/0.24 inchPackage content: 26pcs Plastics Spindle GearsIs there any advantages of the product?It is engineered from durable polymer for lightweight operation, reducing rotational inertia in compact mechanisms.