Stainless steel roll plates which protect the air springs and help increase load capacity of the springs by up to 10% Stainless steel braided air lines for added protection against sharp edges and road debris Stainless steel air spring mounting hardware Jounce bumper inside the air spring absorbs shock and can be safely run with zero air pressure Military-grade AN fittings simply thread together for a metal-to-metal seal, ensuring an easy-to-install, leak-free system with no air line cutting required Does not fit if vehicle is equipped with factory air suspension.