This reusable flat screw cap will work with our 48mm mouth bottles. Replacement caps for 1 Gallon Square Bottle to 2 Gallon, 3 Gallon, 5 Gallon Bottles. If you are using it for other bottles, please check the mouth first. Please note: Colors of the cap will randomly be chosen. Not all bottles have same size mouth and cap may not work with all other bottles.