Being environmentally friendly is excellent, especially when green options can compete with their not-so-green petrol counterparts. Li-Ion battery technology has gotten good enough that Ryobi's new 40V weed whacker can hold its own against my Honda industrial gas trimmer, with one caveat -- if only it didn't get clogged literally every 10 seconds!!! It is useless on anything but Astroturf out of the box! I would give it five stars, except in an effort to save two cents, they cut corners on the plastic leaving a large gap between the end of the pole, and the rotating head. The effect is that I spend more time tearing grass out of the front than trimming the grass, making this an unacceptable design flaw. I love everything else about this trimmer, so I broke out some CAD software and designed a device to help keep grass away from the shaft, and its crevice that does such a good job of trapping grass in it. A great product with so much potential, hampered by pennies of plastic missing. Good thing we have FDM printers and Thingiverse! This thing is a two-part shield for the head of your Ryobi trimmer, model number: RY40220. It’s a bit crude, and I planned on making it look smoother, but this thing really works! By narrowing the gap that the grass can fit through and diverting it into an up and down sort of nature, instead of the grass just going straight in (it would have to go up under the shield, and then towards the center now), I can now mow through tall, thick grass without a hitch, even with the attachment screws sticking out (but trim them if your screws stick out much more than a few mm). Its unbelievable what a difference this makes! You have to try it to believe it... this trimmer used to bog down on any grass that hadn't been touched in a week (basically requiring cutting every 3 days to make it work), but now it can mow through grass on the berm that has been slightly neglected, and a bit messy. This thing will turn your 2-3 star, almost kind-of-close-to-perfect-except-awful 40V electric trimmer into a lean, mean, grass clipping machine, that also is better for the environment than most gas trimmers! You're welcome Ryobi. Don't sue me and I won't charge you licensing fees :p Free for non-corporate open-source hacking/making use, i.e. average joe/jane can download and print for all his/her buddies, but hands off Ryobi, you had your chance in this product's prototyping stage. I don't care if you use this commercially for your yard maintenance business either, even though that would technically be "commercial use". Download now!! Burning coal still produced harmful emissions. To really beat those petrol-heads, we need alternative energy sources!It prints in two halves, I chose to print it standing up as it would go on the trimmer to ensure that the circles were perfectly round (print as oriented), even though this is designed with VERY loose tolerances (the part of the trimmer it attaches to appears to have been as well). No supports; I didn't need a raft either. It looks like it needs supports, but mine came out fine. 80% infill, 1 shell, .2mm layer height, using Ryobi green(ish) ABS is recommended for aesthetic pleasure, thermal resistance and overall part longevity. Once it cools, clean up the few strands of plastic from lack of supports, and pop it on your trimmer. Insert (3) 1/2" 10-24 machine screws (McMaster-Carr PN: 91773A242 or equivalent). I usually design in metric, but I had English screws already available. Function test your machine. Once you have verified that your modification to your trimmer has not compromised its function or safety in any way, equip your body with necessary safety measures (goggles, muffs, etc.) and go clean up your lawn with newfound efficiency!