1988-S4x, 1988 U.S. Spring Charity Seals, Red & Blue Country Hearts Pane, 88-66-T2-4, self-Adhesive, VF, MNH. Never folded, shipped flat.
Issued 1988 by the American Lung Association. Two (2) different red and blue quilt-like country heart designs. Die cut pane of 15 (3x5) seals, SE4S, margin at top, 2 different quilt-like country heart designs, "88-66-T2-4" on margin.
The American Lung Association (ALA) issues TB Charity Seals twice a year. U.S. National Christmas Seals before or at Christmas, and U.S. Spring Seals before or at Easter.
Spring Charity Seals are also known as TB Seals, and are usually classified as Charity Seals, or Cinderella Stamps.