Nuby's NEW Active Sipeez™ Stainless Steel Flip-it Clik-it features a double wall insulation that keeps liquids cool up to 6 hours. The cup is sweat-proof so it won't leave water rings! It also comes with our patented No-Spill soft silicone straw that is safe, easy to clean and simple to assemble. The top is an easy to use push button top that keeps the straw sanitary when child is not drinking. The Durable Kid Proof Base minimizes damage from drops.