Stainless steel mug The Uplus stainless steel water cup uses double-wall vacuum insulation technology to keep the temperature up to 8 hours, enough to meet daily needs. Our LIDS feature sealable press-in LIDS that slide closed to control spatter and lock in temperature, then slide wide enough for easy drinking and reusable straws . Soft to the touch and easy to hold, ade of 18/8 professional grade stainless steel, to ensure pure taste, no flavor BPA free and non-toxic. No toxicity, no worries. Retractable straw hole seal: A tight fitting plastic cap with a sliding lid prevents drinks from splashing and spilling. Warm tip: Do not place in the dishwasher, microwave or refrigerator. Hand washing is recommended to protect the finish.