100% Silicone. Microwave-safe. Will not melt if placed near ovens or grills. Dishwasher-safe. Freezer-safe. Insulates Hot & Cold. Will not break, crack, chip, fade or scratch. Sturdy enough to hold liquids, flexible enough to carry in your pocket. Perfect companion for indoor & outdoor dining, camping, tailgating, commuting. Reusable cup helps reduce waste. 3.75" dia x 5.75" h.