Our tumblers are made from durable 304 stainless steel, double-wall insulated, and vacuum-sealed, keeping drinks cold for up to 24 hours or hot for up to 4 hours. All blanks are BPA-free, lead-free, non-toxic, and food-safe, making them ideal for gifting, resale, or bulk business use. Powder-coated, electroplated, pre-sanded stainless.