Most of us use switches every day in various forms. And although there are sometimes general norms in countries as to which direction is "on", there is variation between countries. So when ...
What is the reason many elevators have concave shaped buttons. Like this: Any special reason behind this?
Perhaps you've seen one of these before. A couple of inches above and below the magnetic stripe reader are protrusions that allow just enough room to swipe a credit card. The barriers are a ...