4 blades come standard on the CP572 tractor mount 72” rotary bush mower. The Brush Bar helps to funnel brush under the Brush Cutt to the waiting blades. The double arch design of the push bar works to pull the taller, heavier brush to the hardened blades, making quick work of woody brush and saplings. If you have a 45 to 75 Hp tractor then adding a 3-point hitch rotary mower Brush Cutt attachment will help you maintain fence lines, improve pasture land as well as lane and road side weed control rough cut grass cutting.