The Grass Gator heavy duty replacement trimmer head will fit 99% of all straight shaft gas trimmers, including Ryobi, John Deere, Echo, Stihl, Craftsman, Toro, Cub Cadet, Troy Bilt, Poulan. Designed for heavy duty gas trimmers with engines of 25 cc. or more. For cutting both grass and weeds. Tough nylon blades. Easy to install, without tools, and is easy to use.