This is a 4-piece trunk cardboard lining board set specifically made for the 1966 and 1967 Buick Riviera.
These are the black cardboard panels that line the inside of your trunk – they cover the sides, the rear, and other areas to hide the metal and give it a finished look.
Brand is unbranded, but they're cut to the correct shape for that Riviera.
If your original liners are warped, torn, water-stained, or just plain missing, this set will restore that factory appearance.