Now you can turn your STIHL YARD BOSS® into a quality wheeled trimmer, adding ease and convenience to your trimming tasks – all for much less than the cost of a dedicated trimmer mower. The STIHL FS-MM trimmer attachment features a dependable STIHL AutoCut 25-2 trimmer head for precision cutting tasks. To advance the line, just tap the trimmer head against the ground. Need to change the trimmer head?