The 14oz. Kobuk Camping Mug has a stainless steel outer wall and polypropylene inner wall. The double wall construction protects your hand from the heat while you enjoy your drink and the ergonomic polypropylene handle provides a comfortable grip. The clear AS lid with slider closure protects your drink between sips and the base pad keeps the mug from slipping on the table top. The Kobuk 14 oz. mug is the perfect fit for most single serve coffee brewing systems. FDA compliant and BPA free.