What the other reviewers fail to mention, maybe because they failed to try, is that the AFS on the trimmer continues to work flawlessly with hand wound string, and at less than 1/4 the cost it's seems like a huge waste to buy the pre-wound spools. It only takes 2 minutes to rewind a spool, so even when I do run out in the middle of a job, I just look at it as a 2-minute break from yard work. Of course, if your one and only concern is convenience, you may be looking at the right product. Be aware, if you've had trouble with rewinding trimmers in the past, it may be because you're using old line, which tends to get brittle over time. Buy some new line and try again. If you buy the three-pack of spools three times, you just paid for your trimmer again.Thanks for reading,Adamps. Two stars for effort, but the cost is just ridiculous.