8-1B.6, WX3d, 1908 U.S. Red Cross Christmas Seal Type 1B, F, NG.
Issued 1908 by the American National Red Cross. Designed by Howard Pyle. Lithographed by the American Bank Note Company.
Type 1B, perf 12, carmine and green, 251/2x261/2mm, fresh, no gum but visible gum breakers.
Christmas Seals are also known as TB Charity Seals, and are usually classified as Charity Seals, or Cinderella Stamps.