Review on Estilo Glass Water Bottles 18 oz with Stainless Steel Cap - Case of 6: Hydration Quenched! by Pedro Hague

I bought these to market and resell for a charitable fundraiser. They arrived safely and the lids work well. However, it turned out that it was covered with foil on the outside and there were black dots on the bottom of the inside of the glass. I've tried soaking and cleaning them. There's no way I can resell them and not knowing what the black pieces are I'm afraid even to use them for personal use as the contents will be swallowed. I have ordered other bottles in the past with great success and decided to try these as they are 18oz instead of 16oz. I will never order them again and will return to other sellers with a more reliable product.