Double Keyboard Bumps
The F and J keys on your keyboard have bumps below the letters, which you can see if you look closely. Apparently, they were included to provide the user with a better sense of where their fingers are located. To type correctly, your right index finger should be on the letter J, and your left index finger should be on the letter F, assuming you have the proper typing form.
Double Keyboard Bumps
Measuring Tape Metal
The measuring tape is equipped with a little bit of metal at the end for added stability. Supposedly, this is beneficial when you need to use the tape on your own for some reason. Alternatively, you may just wrap it around a nail or screw as you go about your business. It is also serrated to make it easier to mark the surface on which you are working when you need to mark it.
Measuring Tape Metal