This is a parametric rim reinforcement for plastic bottles. I made it for hanging bottles in my hydroponics system. The 107mm STL fits my 2L Mountain Dew bottles.Cut your plastic bottle. Determine the diameter of the opening. The only way I could find to reliably measure mine was to flatten the opening and measure the length. Then double that to get the circumference. The diameter can be calculated from there. Edit the SCAD so that 'rim_id' equals your diameter. Compile. Print. Fit the reinforcement on the bottle opening. Poke holes in the bottle inline with the printed holes. Zip-tie it secure.