Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3363701.

This is a replacement cap for a Enviro-Bottle 5 gal jug (3 Gal should be the same). It may fit other 5 gallon bottles

Thread go all the way to the top. you may want to add paper seal in the cap to prevent leaks like the originals came with.