We start with manufacturers that have products our customers want and see if they are willing to have the product subjected to our rigorous testing by one of the national, accredited laboratories we use. If they agree, samples of the product identified by manufacturing batch number, we test every manufacturing batch since there can be changes between batches, are shipped to the lab(s) where they are analyzed and tested. Manufacturers may produce a special manufacturing batch that meets our specifications. If the product passes, we order the product in and list it on our website.