Discontinued some time ago by Nissan, these rubber seals are an important part of the long term function of your early Z deck lid. They keep moisture out of the "cutouts" in the roof area where the deck lid hinges attach. Because they are generally hidden, out of the sun, and not stressed, it is quite possible your originals are still in acceptable shape. If however your original cover-seals are damaged or missing, then you need this kit.
Although these are almost identical, there is a left and a right.
Datsun 240Z, 260Z, 280Z
1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978