Chemistry of Tea travel flask - vacuum insulated

Enjoy your tea with theaflavin, which adds bitterness to black tea; L-theanine, which alters your brain waves to promote relaxation; and of course everyone’s friend, caffeine… not just in the beverage, but also printed right on the flask. Science! Nothing is a better thermal insulator than… nothing! This stainless steel flask’s double walls contain as close to a vacuum as you can get. Vibrating molecules like other molecules to bounce against - that’s how heat transfer works - like a cue ball bouncing around a pool table, transferring energy the other balls. When there’s nothing to bounce against, for example the vacuum part of the vacuum flask, the heat energy stays within the system! Thus, this flask will keep your preferred beverage at whatever temperature it starts, for a good, long time. 18 oz / 500ml capacity, hand wash, stainless steel (silicone ring in cap)