I could not find filter wrenches to fit my water filter system to 3D print and the commercially available ones were very expensive so I designed my own! Additionally, I made them to nearly max out the A1 mini bed so they can be large but support the most printers. Even with the shorter handle I had no problems getting the filters un-done. Much easier to use that a strap wrench!

They fit the following 6 or 12 rib water filter housings:
~ 9.5cm or 3-5/8" diameter

~ 7.5cm or 3" diameter

I recommend printing in PETG but I believe PLA works as well. Let me know how it works if you print it in PLA.