The Siliskin Straw Cup is 100% silicone with an embedded stainless steel ring. It won't collapse when gripped and the universal silicone straw top prevents big spills. Seriously the best cup on the market. Perfect for smoothies, all beverages, the nightstand, tabletop, indoor and outdoor use! Comes as full set with cup, universal straw top and reusable silicone straw.