Zak Designs Clarion 20oz Double Wall Straw Tumbler - keeps drinks cold and prevents condensation, Periwinkle Clear One tumbler with 20 oz capacity. Double-wall insulation keeps drinks cold for longer and prevents condensation Press-in lid with silicone gasket won't pop off and reduces splashes and spills. Wide straw is great for thicker drinks, with stopper on bottom to prevent loss. BPA free, dishwasher safe, do not microwave.