FOR BIG SIPS ON THE GO. We simplified sipping with the Rambler® Bottle Straw Cap. Just flip it open, take a sip, and close it tight to stay moving. It’s leak-resistant, easy to carry (thanks to the TripleHaul™ Handle) and accommodates our wide straw, so you get more drink with every sip.The Straw Cap is compatible with all YETI® Rambler® Bottles. Use the measurements below to cut straw according to your bottle size. 12 oz - 4 5/8" 18 oz - 6 5/8" 26 oz - 7 1/4" 36 oz - 7 7/8" Please note: Do not use the Rambler® Bottle Straw Cap with hot or carbonated beverages or for storage of food or perishables.