Our high-quality, durable, and BPA-free sublimation tumblers are seamlessly constructed of stainless steel. Makerflo tumblers are high-quality, durable, and BPA-free making them an all-around favorite crafting blank. These tumblers are "sweat-free" to keep any beverage toasty warm for up to 8 hours, or refreshingly cold for up to 24 hours.