21 inch. 2010 model. New price approximately $500.00. Little used, to cut approximately 800 square feet of lawn for eight seasons. Includes side discharge adapter, mulching plug, grass catcher that has never been used, owners manual, newly sharpened blade, 160 cc Honda engine. Originally self propelled but drive mechanism has been permanently disconnected. Looks and runs great. Reason for selling? -- upgraded to a Lithium Ion battery powered mower.