Review on Speed Feed 450 Trimmer Head By Stens - Faster And More Efficient Trimming by Victor Halla

the first time I tried to install on my stihl 90 the green adaptor would not screw on the shaft so I decided to send it back but tried once more by starting a little backing off then tighten a little more after about 5 try's it finnaly went on so it will fit I think all or most stihl weed eaters I think the starting thread is a little rough I read other reviews that had the same problem but one review said that he done what I had done I tried that and it worked so keep trying and good luck o take pictures or go on tube and watch very closely will save a lot of time they show all assembly of 400 and 450 is great help