The Libre glass’n poly large (14.3 oz.) is the perfect tea gift with a ‘big gulp’ of tea. It has a health-conscious glass interior for fresh taste and a durable poly Tritan exterior for "on the go" durability. The stainless steel tea filter is surrounded by BPA-free polypropylene as is the lid interior. It can be used 2 ways to brew and travel with loose leaf tea – tea in the tea glass or tea on top of the twist off filter.