This is a high-quality Hyper Tough H2500 crank case and flywheel designed for 2-stroke engine types. It is made of durable aluminum material and is compatible with Hyper Tough H2500 string trimmers. The package includes one crank case and one flywheel, making it an excellent replacement part for your outdoor power equipment. Upgrade your string trimmer with this reliable and efficient Hyper Tough H2500 crank case and flywheel.