I replaced the horrible factory head on an inexpensive Homelite with one of these and it works great. Using it with four lines on a low powered trimmer is okay but it's slow to spin up when you press the throttle. I also had to place an extra washer under the head (only one was supplied) to keep it from wobbling on the Homelite. The heavier line does a good job and barely shows wear compared to the original. I've only had it for a short time so it remains to be seen how well it will hold up.