Everyday Objects That Secretly Have More Than One JobDid you know that some of the most common items we use every day are working double duty? Here are some objects that have hidden features that make life a little easier. The raised bumps on the F and J keys help you position your hands correctly without looking at the keyboard. The tiny hole in padlocks helps drain water and provides a spot for lubricant if the lock starts sticking. The black dots around a windshield help protect the adhesive that holds the glass in place.