Features Cast steel material, the gear will provide greater overall strength, durability and wear‑resistance. Transfer the torsion of your servo into a gear train with these MOD 0.8 servo gears. 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. This gear reduction will increase the torsion at the hub gear to 5x what the servo produces. With 25-teeth spline MOD 0.8, easy to install and use, long service life. Specification: Item Type: Servo Gear Material: Cast Steel Product Model: 4307-1025-0020 Product Specification: 20-tooth servo steering gear (25 tooth spline MOD 0.8) Pitch Diameter: Approx. 16mm / 0.63in Outer Diameter: Approx. 17.6mm / 0.69in Package List: 1 x Gear Package List 1 x Gear