15 card sheet-- available as a mail in offer from Topps- 13 of 28  the Team Leader cards and team checklists... Other 2 cards are unnumbered checklists  for cards 1-264 & cards 265- 528.   These 2 cards are found not in set or wax packs but on on the mail in sheet--- very scarce   Thinner stock, pre folded for mail. Includes Cowboys ( Dorsett)-- Seahawks ( Largent)-- Steelers ( Franco Harris)------  really nice shape-- 10 1/2" x 13 "--- rare in any condition--- free shipping