Stanley The Stay Smooth Straw Topper 2 Pack. Sipping just got even better. Ergonomically designed for pucker-free sipping, the Stay Smooth Straw Topper contours to your mouth’s natural shape. Made of silicone, it fits the Quencher® H2.0 FlowState™ Tumbler or the Stanley Cross Bottle straw and is reusable, dishwasher safe and BPA-free. In classic neutral tones so you can mix or match colors and keep your hydration glow going. Soft silicone. BPA-free. Ergonomic design. Dishwasher safe. Imported.