I wanted a glass cup I could actually take with me, and this Glass+ Travel Tumbler 19oz fits that well. The glass interior means nothing tastes off, and the insulated stainless steel outside keeps drinks cold without sweating on my desk. It is 100% plastic-free, which was the main reason I picked it over other tumblers. It is a bit heavier than an all-metal bottle, so it is not the lightest option for long walks, but for commuting and the office it works nicely. The lid seals fine for carrying in a bag upright.