If you've broken you broken the loop on your water bottle (in our case it was melted in the dishwasher) this thing can provide a replacement. Use the customizer to size the inner loop. The smaller loop will fit a standard key ring type carabiner. The loop is only 1 mm thick so this prints fast and easy with just a small amount of filament. I used ABS, but I suspect PLA will work (although it may be a little less strong).
UPDATED: The original design broke when my daughter used it so I've made the design stronger. Let's see how this one survives.