The glass straws are made from borosilicate glass, the most durable commercially available glass. It is resistant to thermal shock , meaning it can withstand incredibly high and low temperatures. The straws are dishwasher and child safe. They do not conatin lead or any other toxins. The gorgeous RESTRAW sleeves are made from 100% hemp fabric, and are antibacterial and antifungal.Each sleeve is designed to carry one RESTRAW and one cleaning brush so that they fit comfortably.