Our 21in High Lift Mower Blade is designed for use with the MILWAUKEE M18 FUEL 21in Self Propelled Dual Battery Mower (2823-20). The steel blade offers you increased durability and longer life. The precision machined cutting edge and increased blade angle deliver an improved cut quality. The optimized high lift mower blade teeth shred grass and debris into finer pieces for improved mulching and bagging performance.