Many backpacks have this small leather patch on them. It’s actually quite useful when you’re camping: you could let ropes and hooks through it. Today, it’s mostly an accessory.
A hole between the camera lens and flash on iPhones
Few people know this little hole is actually an auxiliary microphone. It makes the sound on recordings clearer, helps Siri understand accents, and reduces the noise captured by the main mic.
The number 57 on Heinz ketchup bottles
It may seem to be a part of the design or the number of ingredients used. However, if you tilt the bottle and hit it with your palm on the number when ketchup doesn’t flow, you’re in for a big surprise.
A code on makeup bottles
Any cosmetics package, be it eye shadow or powder, contains this small open container symbol, labeled 6M, 12M, or 24M. This labeling indicates the shelf life of the product in months.
A simple trick: write down the date after which your makeup will become useless by adding the number of months to the date of opening.
Replaceable blades on a box cutter
Lots of people don’t really know that a dulled blade of a box cutter can be broken off to get a new and sharp one. It’s not dangerous if done correctly: let the dulled blade out, take off the clipper, fix the blade with a hole in the clipper, and break it off easily.
A switch on the rearview mirror
This is a day/night switch that protects the driver from being blinded by the headlights of a car behind them at night. Rearview mirrors have a double reflective coating that you can switch by pressing the button. This trick will be especially useful for novice drivers.
