Made of aluminum alloy + steel material, low density, high strength, strong conductivity. Lawn mower accessories universal head gearbox and complete set of accessories. Specifications: 26mm Casing Inner Diameter. Condition: 100% Brand New Material: Aluminum alloy + steel Color: Sliver Diameter: 26mm/28mm The quantity of tooth: 9/9 Package Included: 1 x Gear Head