Features: - Cold Sensitive Glass - Logos on Both Sides of the Glass (2 Logos) - The Perfect Gift! - Always Know Whether Your Drink is Lukewarm or Cold - Show off your USA Patriotism at Home or Work - Perfect for Your Favorite Ice Cold Beverage - Amaze family, friends, kids, co-workers and allow them to witness "magic" right before their own eyes! - A SEATTLE BRAND Special Care Instructions: - Wash Before First Use - Hand Wash ONLY - Gently wash outside of glass with soft sponge or simply with just water and soapsuds to preserve color changing print - Avoid using tough or rough cleaning tools on outside of glass - Avoid scratching glass with sharp objects or picking at design to help maintain color changing print - Not Microwave or Dishwasher Safe! (Due to the sensitive nature of the color changing print) Product Details: - 16 Fl oz/473 ML - Lead Free - Cold liquid needs to be a maximum temperature of 10C/50F (cold tap water) in order for glass to change colors - Recommended temperature is around freezing level -6.67C/20F (ice cold water) for optimal color changing - Note: Before color change, when not in use, logo on glass may change color even without cold beverage inside it due to cold room temperature. Rinse with warm water to change back to beginning stage (clear-ish white logo) - After color change, you might also notice logo temporarily change back to original color (clear-ish white) if you touch with your hand due to warm body temperature