SUPERIOR SIPPING: Enjoy your drink to the fullest al fresco. The smooth ceramic lined interior, classic wine glass shape, and thin lip directs flow across your palate, emphasizing flavors, while the weighted base feels pleasantly robust in your hand. TRUE TASTE CERAMIC COATING: Your drink should taste how you intended. Unlike stainless steel, our ceramic interior coating keeps your beverage pure and free of lingering odors, oils, and "old penny" tasting notes. SUSTAINABLY: Durable and BPA-free, Ruby gets better for the planet with every refill when used in place of a disposable cup. DRINKABLE THIN LIP: The tapered thin lip is comparable to that of a fine dining wine glass for great tasting easy sipping and a wide mouth allows you to take in the full aromas of your beverage for an amplified drinking experience. 12 HOURS COLD, 3 HOURS HOT: Our 304 18/8 double-wall vacuum-insulated stainless steel tumbler stays cold for up to 12 hours and retains heat for up to 3 hours. Plus the unique splash resistant swivel pebble lid provides extra security while you sip. Experts in coffee with a love for product design, we at Fellow believe coffee is a journey. We are dedicated to melding beautiful design with flawless functionality to help aficionados and beginners alike find the fun in the brewing process.