Here are some other lesser-known tips:

• The Extension Screwdriver  : Some screwdrivers can  be inserted into an open-end wrench  for better grip and leverage.
• Fabric swatch on clothes  : Allows you to  test a detergent before washing it,  to avoid unpleasant surprises.
• Brass door handles  : This material has  natural antibacterial properties , limiting the proliferation of microbes.
• The small triangle on the fuel gauge  : it indicates  which side  of your car’s tank is on. Handy at the gas station!

Conclusion

This  small hole under the padlock  is  a perfect example of intelligent design  : discreet, but  essential .

This proves that  simple details  can improve  our daily lives , without us even realizing it.

So the next time you use a lock, you’ll know why the lock is there…and how to get the most out of it!