a silicone or plastic lid to pop over the can top could keep the pressure differential from sucking your beverage out of the can... have a couple different sizes and inserts to handle your odd sized cans...soda canscoming towards or through can be a little different due to regional can suppliers for a few things out there...if you wanted a rolling example...
if the chains on that charger were attacked to something substantial I might think they were for moose anti intrusion, Volvo and Saab used to design their cars to keep the moose from ending up in your lap or face if you hit one on the roadway. moose are tall/long legged so generally they are gonna be on the hood or through the windscreen and highly likely to kill you if they intrude into your cockpit in a car...well a bike...it is gonna leave a mark if you hit one, much bigger mark than the deer or even an elk...
Moose are pretty heavy and the long legs for wading in bogs and grazing, or crossing streams, etc... Moose are pretty good swimmers.
David