These beautiful clear glass straws are perfectly sized for half gallon (64oz) Mason jars! That’s the huge jar, 2 quarts. Fill it up with water, set it on your desk, and monitor your water intake throughout the day. This isn’t a jar you will want to be carrying around much. I’m assuming that most people who want to drink half a gallon of anything will be drinking water, but the 9mm straws are also great for smoothies, milk shakes, protein shakes, yogurt, blended drinks, and more! Our reusable glass straws are made of the strongest glass on the market, so these straws will not break easily. Pyrex® products are also made of borosilicate glass. They also will not leach any chemicals into your beverage like plastic can. Each order includes four extra long glass straws plus one straw cleaner. This 9mm outside diameter, 6mm inside diameter straws are 30cm (11.8″) long, the perfect height for a half-gallon (64oz) jar. Glass straws are fun because you can see the liquid rising up through.