Stens Notched Air Lift Blades create significant air flow that pulls grass blades upwards for a clean, concise and uniform cut. By pulling grass blades to stand up straight, air lift blades can cut them all at the same height for greater consistency and a more manicured appearance. These blades are ideal for thick and lush lawns because of the strong air currents they produce. Powerful air circulation quickly and efficiently discharges clippings. Because of intense air circulation, notched air lift blades are not recommended for lawns with thin or bare spots that could result in dust and sand being kicked up. Notched air lift blades are best used on mowers with more powerful engines. For lawns that are thick and vigorous, Stens Notched Air Lift Lawn Mower Blades will produce a professional looking cut that makes lawns look luxurious. Specs: Description: Notched Air-Lift Blade, Length: 18 in., Center hole: 1/2 in., Width: 2 1/2 in., Thickness: 0.250 in., Heavy Duty: TRUE, Requires 3 for 52 in. deck Replaces OEM Numbers: Grasshopper: 320239, Woods: 70104, 70117 Compatible With/Replacement For: Grasshopper: 3452, 6052, 6152, 9052, 9252, 9352, 9552, 9652 and 9852; requires 3 for 52 in. deck, Woods: Requires 3 for 52 in. deck Stens 1 year warranty ensures reliability and performance for every part. We're confident that our products will work flawlessly, but in a rare case that it does not, we'll replace it anytime within one year of your order. Stens branded parts are trusted by professional dealers to perform OEM quality repairs. The Stens name is featured on all Genuine Stens product packaging.