TRIPLE INSULATION TUMBLERS - Our 16oz. Tumblers are crafted with triple insulation to keep your drinks hot for up to 12 hours and cold for up to 12 hours! Say goodbye to lukewarm drinks and hello to refreshing sips all day long. FLIP TOP LEAK-PROOF LID—Our stainless steel tumblers come with a flip-top lid and comfortable sip. The flip-top lid has a rubber seal that keeps it totally leak-proof to prevent leaks and drips and keeps your coffee/tea, etc.… hot as can be.