Dosko chipper/mulchers from Great Northern Equipment feature a 3-in-1 flail system. The double-edged flails have been heat-treated to 60 RC hardness, can be sharpened on both sides and are reversible. Both the 13-16T-13H and the 2022-20HE are towable and powered by Honda engines. www.gnedi.com/Public/Portal.aspx