Teflon Tape

Also known as plumber’s tape (pictured), this thin, nonstick product helps seal the connection between the pipe and the new showerhead, preventing leaks. About $1 at hardware stores.

Adjustable Pliers or Wrench

Look at both your new and old showerheads where they screw onto the shower arm. If you see two flat indentations, you need a wrench to remove the showerhead (or screw it on). If you see a ring of small grooves, you need adjustable locking pliers with ridges on the jaws (such as a Vise Grip). Each tool costs $5 to $10 at hardware stores.