The Oversized Oasis Built For Icy Agua Frescas, Colossal Cold Brews, And (Most) Cup Holders. The Rambler Straw Mug is built to house 35 ounces of your favourite cold beverages, this is one hefty hydrator. Supremely insulated and made with an elevated handle and a cup holder-compatible design, it goes best with overly large cold brews, cross-country trips, and absolutely massive mocktails. And with our fan-favourite Straw Lid, you can say goodbye to single-use plastic straws.