Agrimetal Aerator wheels ride on sealed ball bearings! This is maintenance free. Competitors use bushings only. Wheels can be fitted with heavy 3/4" coring tines or rugged slicing knives. 8 tines or knives are standard per wheel. The Agrimetal FA720 is designed for heavy duty uses on your biggest aeration jobs. The design is simple and proven. The 6 foot working width lets you cover up to 50 acres per day. The FA720 is your perfect choice for aerating fairways, school grounds, sports fields and parks.