These beautiful clear glass straws are perfectly sized for half pint Mason jars! Also ideal for wine glasses, coffee mugs, rocks cocktail glasses, and martini glasses. All-purpose size – Great for smoothies, blended cocktails, milk shakes, protein shakes, yogurt, drinking water, milk, juice, iced tea, coffee, soda, and everything else! Our reusable glass straws are made of the strongest glass on the market, so these straws will not break easily. Pyrex® products are made of borosilicate glass. They also will not leach any chemicals into your beverage like plastic can. We recommend buying a straw cleaner, but they are also dishwasher safe. These 9mm outside diameter, 6mm inside diameter straw are the perfect height for a half-pint (8oz) jar. These straws are cut from glass tubing and the ends are polished by hand. Because of this, there can be small variations in the diameter. Glass straws are fun because you can see the liquid rising up through them like in a disposable straw.