You use a DOT-helmet to protect your brain, right? Why would you choose not to provide your cherished frosty beverage with the same government compliant protection?
These classic DOT-approved ATGATT Koozies are made out of sturdy 3mm thick neoprene, not that super cheap foam that will only last one party. These things are ready to live a life under your seat, ready to spring into action and keep your chilled beverage of choice at an optimal temperature whenever called for duty. And because life is too short to drink warm beer.