4-line cutting system replaces bump-and-feed gas trimmer heads. Interchangeable with 3-bladed systems. Easy-to-install. Excellent for fine edging along walks, drives, and foundations. Fits most Ryobi, McCulloch, Toro, Homelite, and Echo gas models. For specific model assistance call CMD Products, 800/210-9949. Refer to model No. 5610 (SKU 700016) for replacement trimmer line.