Insulation: Firewall 68-72 GM A body w/ ACThis goes on the INSIDE of the car up on the firewall . helps limit the heat transfer into the cabin. Precut with a harder outward surfaced that faces the passengers This one is if LHD cars with FACTORY AC. Fits: 68 72 GTO Le Mans Tempest 69 72 Pontiac GP 68 72 Buick Skylark GS 68 72 Chevelle, El Camino, 68 72 Olds Cutlass 70 72 Malibu