1. Transfer the torsion of your servo into a gear with these MOD 0.8 servo gears.2. This 20 tooth servo gear is most commonly used to drive the 100 tooth hub gear, spaced 48mm away, in order to create a 5:1 ratio.3. Using high quality brass material, and sturdy, wear resistant, long service life.4. This gear reduction will increase the torsion at the hub gear to 5x what the servo produces.5. Professional manufacturing, exquisite workmanship, easy to install and use.Specification:Item Type: Servo GearMaterial: BrassProduct Model: 4305-0025-0020Product Specifications: 25 Tooth Spline 0.8 Module Pitch Diameter: Approx. 16mm / 0.63inOuter Diameter: Approx. 17.6mm / 0.69inPackage List:1 x Gear