Opening a bottle of carbonated drink, which turns out has been shaken, spews suds all over—everyone must have encountered this embarrassing moment before.
The design of the Angry Bottle Cap is made just like regular plastic bottle caps, but with modification: the top of the bottle cap is made with soft silicone. When the bottle has been shaken, the pressure in the bottle increases and pushes against the silicon top of the Angry Bottle Cap, causing it to bulge. This bulge is a reminder for anyone trying to open the bottle, saving him or her from soda 'explosion'. When the carbon dioxide has dissolved, the bulge will settle down, signalling that it's now safe to open the bottle.