Fire Extinguisher Bottle Cap

This is a cap to utilize a spent Kidde fire extinguisher (https://www.kidde.com/home-safety/en/us/products/fire-safety/fire-extinguishers/for-home/466179n/) for other purposes. After printing, an o-ring can be fitted to make to bottle hold water. I don't use extinguishers very often, but feel guilty disposing of a nice aluminum bottle when I do.