Material - The brush cutter gear head is made of high quality aluminum alloy and steel. It is rust-proof, corrosion-resistant and has excellent oxidation resistance. Gear head sizes: Inner diameter 28mm + 9 splines. You can choose as needed. Replacement Part - The brush cutter gear head is the ideal accessory for the trimmer; it would replace your old or broken ones very well. Compatible - The brush cutter gear head can be normally used for brush cutters, trimmers, lawn mowers, etc. Easy to replace part, it is simple and convenient to connect the trimmer. Wide Applications - The lawn mower gear head has stable performance and good working conditions, ideal for gardening, agriculture, animal husbandry, breeding, and forestry.