Which of the following is not a real type of brake pad?

• Organic brake pad
  There are several different types of brake pads including metallic brake pads, ceramic brake pads and organic brake pads. How Brake Pads Work
• Ceramic brake pad
  There are several different types of brake pads including metallic brake pads, ceramic brake pads and organic brake pads. How Brake Pads Work
• Plastic brake pad
  There are several different types of brake pads including metallic brake pads, ceramic brake pads and organic brake pads. How Brake Pads Work