This is a high quality made in Italy Tecomec (300mm - 12") Universal Pro-Trim head. This head fits Stihl, Husqvarna, RedMax, Ryobi, Echo, Craftsman, Honda, COOCHEER, and most major brands of gas-powered trimmers. The Tecomec Pro-Trim flail blade system creates less resistance (load) then most nylon line trimmer heads, developing higher rpm for superior cutting performance with most gas-powered trimmers. The tough Pro-Trim cutting blades have extremely durable beveled edges for long life. Made of high-impact nylon, they withstand heavy-duty operation in the toughest cutting conditions. These double-edge blades are supported by metal bushings and retract fully upon impact with a solid object, preventing damage to the blades and structures. This pro-trim head is recommended for trimmers up to 40cc.