It’s a mug, a thermos and a bottle. 16oz’s of durable double walled construction and vacuum insulation keeps hot drinks warm for 6 hours and cold for more than 24. The new cafe lid 2.0 keeps you spill proof if you’ve got it closed and keeps your coffee or tea hot for even longer! 100% food grade stainless steel won’t impart or retain flavors. Go from lattes to lemonade without a problem. BPA free, toxin free. This Klean Kanteen is literally the best coffee mug in the world and probably the last one you will ever buy except to give to a friend. It’s that good.