Pen Cap Holes
You might have thought something is wrong with the pen cap since it has a hole. Do not worry because this was done by design. The hole was installed so that air can flow in freely if the cap is accidentally swallowed by someone. This makes sense since there are many people who have the habit of putting the pen cap in their mouths when they are deep in thought!
Pen Cap Holes
iPhone Camera Hole
In case you have not noticed, there is a little hole next to the camera lens on an iPhone. The small hole is actually a microphone! Ever since Apple came out with the iPhone 5, all of their smartphones come with three mics. There is one located on the bottom edge, another under the speaker grill, and another one next to the camera lens. They added all the mics to make sound recording easier regardless of how the phone is held.
iPhone Camera Hole
