Basics

A Trademarked Combination of a Water Storage Container and Interlocking Bricks
While not as Ergonomically Ideal as a Jerry Can or as Storage Dense as an IBC Tote or 55 Gallon Drum they do allow for modular setups that fit a space (Such as a home Walk In Pantry or Garage nook better, and allow for Storage/Stockpile Capacity to be built up Gradually (and thus POTENTIALLY more affordably, Financing notwithstanding)
Also unlike a Cistern or fixed Rainwater Storage Tank they are highly portable
Also unlike fixed storage tanks or Large Totes/Drums they also can be moved around and used as small containers without additional dispensing requirements
Main downside is cost/complexity, and slightly slower Filling (ie instead of going from 0% Filled to 100% filled with a tap, or putting a Garden Hose in the top of an IBC Tote etc, one would have to fill all bricks one by one
While they may have more potential failure points per unit of volume stored ( Square Cube Law and all that), in the event of tank failure/leak formation, the lost volume could be confined to one brick and thus only a small fraction of the whole
- An Inventory+Routine Inspection Log is probably in order though for Ideal Use

Sourcing

They tend to come with a Ventless Spigot / Spigot Cap for dispensing
They also sell a proprietary Lifestraw -like Microfiltration based Filtering-Dispenser Pump, but this is Largely Unnecessary with Proper Potable Water Storage or a more dedicated (ie not per storage container) Potable Water Filtration strategy
- Also not required for water that need not necessarily be Potable (although perhaps still mostly “clean”, such as for Flushing Toilets, Rinsing Things Off, For Watering Plants, etc)