Ok, I have been researching on bush trimmer for a bit and finally decided give this a try for the price and two blades. It meets my expectation. There are two blades. The blade is not flimsy and not too heavy either. It would meet my application well, which is thick brush and vine, also tall grass. The blade performs well. The edges are not sharp, but beveled. I tried it as it was and worked ok. Then I sharpened the edge and it worked much better. As I don't have much rock/stone, or cutting saplings larger than 1 inch, I'm pleased to notice that the blade stayed sharp after 1 hour of continuous cutting.Now back to compatibility, the kit comes with 2 adaptor packages. For me, but both will not help Echo 58V trimmer as the echo head does not come with the 1 inch raised part to fit the blade. Home Depot sells an Echo brush cutter package for $49.xx. For Echo trimmer, you might need to buy the Echo kit instead.For Ryobi 40v string trimmer, the blade fits well and will work. The kit does not come with a left hand nut to fit the Ryobi head though. The two nuts come with are both larger. Fortunately the nut in the Ryobi string trimmer head is easy to remove. You need to open the head and push the nut from outside and it will pop out easily. It's a flange nut, put it after the blade, the pressure washer and then the larger cover, tight it counter-clockwise, it's in business. There is a good video on Youtube shows exactly how to remove the nut.
