PlastiColor GMC Logo Easy Fit Mud Guards are the most colorful and durable flaps with a patented, fiberglass backing that not only keeps them from cracking or splitting, but also adds " memory" to keep their shape. They are also made of a specially formulated PVC that will easily withstand sub-zero temperatures and extreme heat without cracking. These " Easy Fit" mud guards feature an easy-to-install design, and includes all the necessary hardware which facilitates easy installation.