UPDATE August 2020- I updated this review to a 5 Star because this line really works well with my DR trimmer, and it really lasts. If I don't hit metal or a woody, perennial weed, like a pricker, the line lasts a very long time. Hitting harder stuff, it does much better than the OEM blue twist line, but it will wear down. The fix for the hard installation is this - grab a propane torch and a pair of plyers (no, you're not going to go "midevil" on anybody's rear end). Cut the line to length, and then use the plyers to insert this line about 1/4" at a time until it comes up in through the spool head, at which point grab it with the plyers and pull through. When you get ends done, get the line 90% snugged up, but not quite looped up into the groove above. At that point, hit line with a little bit of propane torch heat right where you need it to bend up and seat into the trimmer head, and then use the closed plyers to push the line into the groove. Pull line tight. That works great, takes only a couple seconds, and takes the irritation out of trying to get the line loaded. No soaking, no nonsense. The line never breaks at the heat points - at least not on my DR Trimmer. This line is good, and worth the extra bother getting it on. _______ I bought this to try in our DR Trimmer, which is an incredibly well designed machine. The cord fits, but you will need to use line pliers (or other basic pliers), to advance the cord a bit at a time to get it through the spool holes. HEADS UP - the cord is not square in cross section. It is rectangular, with a long and a short side. It will only loop up over the lock tab if you insert in in one of two possible orientations. If it is the wrong way, it will not loop up and stay locked over the tab in the spool on the DR Trimmer. If it is the right way, it will loop up, but you will struggle with it more than with the 2-line intertwined DR cord, which itself is not simple to install. So is it worth the extra hassle at getting it loaded? Well, I used this cord for 1 tank of gas, after going through the learning curve of getting it loaded on the spool, and I'll say that, when new, it definitely cuts better than the stock DR Trimmer cord. It cuts smoother and faster. I use the trimmer to cut 2-3 foot weeds in a field (goldenrod, ironweed, boneset, grasses, et cetera). This line, after installation, is an improvement over the stock line. As the cord wears, and the corners wear off, it cuts more like the stock line. After one gas tank, the line was the same length as when I installed it, and the last 2-5 inches had the corners worn off, so the line was more circular in cross section. I will update after a few more tanks. Definitely a labor saver, albeit not a huge improvement over OEM - but noticeable.