Jason Chen and his friend and partner Mr. Wu, observed in their travels many people drinking tea from poorly designed tumblers. Fortunately Mr. Wu owns one of the largest production companies in Hubei, so he and Jason designed a new tumbler together, one with a larger lid and a larger brewing compartment to accommodate the expanding, brewing leaves. This tumbler seals tightly, so you never have to worry about tea leaking out, even if inverted. Our tumbler makes tea easier to brew, drink, and enjoy on the go. The tumbler is available in double-walled stainless steel, good for holding heat for 4 hours. Brew with confidence anytime, anywhere with these useful tumblers.