I have previously used 5 gallon water bottles for my earthquake preparedness kit, but I can no longer handle the weight of the bottles. So I looked for options. I was very excited when I found Waterbricks. They are 3.5 gallons each and I can handle the weight. Waterbricks can be maneuvered and carried with the removable handle and by putting a hand through each hole.
The Waterbricks have two holes with male and female connectors. The basically connect like logos so they become a cube or a rectangular stack. This makes them easier to store and they take less space. I gained a lot of space switching out the three 5-gallon jugs for four Waterbricks in my emergency preparedness kit. I am so happy with them and recommend them highly.
EXTRA NOTE: Be sure to read the instructions on how to clean them and sanitize them so you safely store water or other food products. It's extremely important to remove the residue from manufacturing, especially when storing water or food.