The John Deere GY20679 54" Replacement mower blades are OEM blades made of steel, designed specifically for John Deere mowers. These blades are compatible with the GY20679 model and provide a cutting diameter of 54 inches, making them ideal for maintaining large yards and gardens. With a California Prop 65 warning, customers are advised of potential health risks associated with the product. These replacement blades are essential for keeping your lawn looking neat and well-groomed.