This package comes with two sheets of pressure-sensitive plastic (also known as Velostat or Linqstat), each sheet measuring 9.8 in x 9.8 in (250mm x 250mm). When you press on the material, the resistance goes down depending on how hard you press. These conductive plastic sheets have a resistance of 500 ohms per square, which is more conductive than other common pressure-sensitive sheets. They are perfect for making DIY pressure sensors and adding a gentle fade in and fade out effect to your project. Just sandwich a piece of this material between your paper switch to turn it into a pressure sensor!