This is my take on a clamp on style Arken EP5 throw lever for the magnification wheel. Namely, I wanted a clamp on style throw lever that also utilized a knob style lever. All the other designs I saw were just flat less ergonomic options IMO. Other than the filament, you just need an M3 flathead hex screw between 8-9 millimeters in length and is really just included as an added measure to prevent the knob from ever wanting to rotate during use. It's very resistant to rotating if installed properly. A couple key notes as it pertains to print settings. - I recommend at most a 0.16mm layer height as it will print the printed threads more accurately/ stronger that way. - Print with 4 perimeter walls and 100% infill for optimum strength/ quality. - Use a filament built for the task and you shouldn't have issues. Examples, PETG, PETG-GF, PETG-CF, CF-Nylon, PET-GF, PET-CF would all be adequate options. - I printed mine on a Bambu Labs P1S using Siraya Tech FDE colored PET-GF filament using the unmodified Generic PET-CF profile provided in Bambu Slicer. (There's no GF option, but the CF option works, dry your filament properly.) - No supports needed. Both components have been designed to be very easy to print. You simply lay the clamping ring flat in your slicer, slice and print. For the knob, orient the screw head side with the conical countersink down toward your print bed, slice and print. Installation: - Take only the clamping ring, and slide it over the magnification wheel so that it's centered in channel around the wheel. - Determine the location you preference your lever to sit in relation to your magnification throw (I feel orienting it so that the lever knob is aligned with the 12x magnification marking on the wheel feels the most natural for me and doesn't block anything else I have on my build.) - Once you've positioned things where you want them, you can lightly squeeze the two threaded clamping halves together and start to thread the knob on. - Ensure the printed threads are aligning correctly between the two halves as you start to tighten down the knob. - Continue tightening the knob down while checking to make sure the indexing nubs are landing in the grooves of the scopes magnification wheel and continue to run the knob down until it bottoms out, ensuring not to over tighten, just run it down until it bottoms out. (This is required to ensure no slipping of your throw lever around the magnification wheel.) - To finish things up, take your M3 screw and run it down into the countersunk hole in the top of the knob and again, ensuring you don't over tighten it (The M3 screw taps it's own threads and over tightening will strip them out, It's not holding the knob on by itself, it simply applies outward pressure for the printed external threads of the clamp so that they engage more diligently into the internal printed threads of the knob.) This concludes the install. Enjoy!