Initially, the blue part of the eraser was intended to erase darker spots on rough paper, as the red part was softer and could not make such paper. But the rumor that the blue part has the power to erase pens, manufacturers appropriated this new purpose and the fashion caught on.
Is this hole just cosmetic? In fact, this device is of paramount importance, as it allows air to flow in case the cap stops in someone's throat.
The idea of adding an extra pocket was from the creator Levi Strauss, based on the needs of the cowboys, who became faithful consumers of the pants. They needed a small space to carry their pocket watches, as at the time men wore this device attached to a chain, which in turn was attached to the vest.
Today, the pocket can be used as we prefer since there is no more use for the watch.
Barely noticeable, the tiny hole in the plane's window allows air to move between the two panes, equalizing the pressure between them. This is due to two pieces of acrylic being used to make the window panes and by itself, the interior glass panel could break due to the significant difference in pressure between the cabin and the side of outside.
The fold was used so that they could be hung on nails without crushing them, because at the time a hanger was a luxury item.
The cylinder in the cable of the charger has the function to avoid variations and energy peaks in the currents that pass through the cable. It is called a “ferrite core” and without it the radiation emitted by the wires could interfere with other electronic objects around them.
Have you ever noticed that the buttonholes on a dress shirt are mostly vertical, but the first and last are horizontal, as well as the sleeves? In places where they are more likely to unbutton easily, the buttonholes are horizontal.
