If you were to look closely at an audio jack, you’d notice it has deep ridges. These bands are there so it’s a tighter fit when the jacks are plugged in, but this is just one of their functions.
The threaded bands are made of an insulating material that protects the wires when sound is being transmitted. What’s more, the number of ridges on a jack will tell you which end goes where.
The Metal Plates on Staplers
If you've ever worked in an office, you're probably incredibly familiar with staplers (and how infuriating it can be when it's stuck). If so, you've definitely noticed the metal plate they have at the front end, and probably assumed it was there as reinforcement to bend the staples. While this is, in fact, one of its functions, it's certainly not the only one.
Your average stapler actually has settings, and that metal plate, called an anvil, helps you adjust them. If you turn your stapler upside down, you can change the setting by spinning the wheel until it is lined up with the hole in the metal plate. This will turn the arms of your staple outward and make it much easier to pull out the staple later if you need to, like a "temporary staple."
The Hole on the Top of a Lollipop Stick
Lollipops will forever remain a childhood favorite. No kids' party was complete without them, and one of the best parts of eating a lollipop was turning the plastic stick with a hole into a makeshift whistle. As fun as that was, that hole actually has a purpose.
When candy makers pour the hot, melted candy into the mold, some of it drips into the hole and hardens, so the candy stays on the stick without falling off and becoming a choking hazard.
Silica Gel Packets
Everybody knows that silica gel packs are there to preserve a product's "freshness." But have you ever wondered how this little bag of tiny beads manages to do that? Silica gel sucks the moisture out of its environment, and they absorb up to 50% of the humidity in an enclosed environment, helping keep things nice and dry.
Next time you buy a new product that has one of these little packets, save it instead of throwing it out — next time your phone falls in the toilet, you can quickly shove it into a handful of these little beads. Definitely works better than rice, and is far less messy!
Rubber Bumps on Your Tires
Chances are that if you're not a mechanic, you probably have no idea these even exist. And why would you? It's not like we go around checking our tires every day. But if you did, you would notice there are little rubber bumps on the tread of your tire.
These raised edges inside the indentations of your tire's tread indicate when it's time to change tires; if the edges are even with the bumps, you should get to the tire shop, fast. If the edges are well above that of the bumps, you're good to go.