These collapsible stainless steel straws are made of food-grade 304 stainless steel, they can easily change length from 3.94″ to 9.05″, fit for 10-30 oz cups and tumblers, really convenient to use. The silicone tip ensures comfortable temperature and never poke your lips while enjoying cold or hot drinks. The collapsible straw and cleaning brush can be retracted into small size and put into the portable case with keychain carabiner, handy and lightweight, perfect for putting in the pocket/bag or tie to your belt wherever you go. They are easy to clean, you just simply insert the long cleaning brush into the center of drinking straws, gently rotate and move it to wash your smoothie straws clean. It’s also dishwasher safe.