This is for an original decal celebrating the 50th Anniversary of Mather Air Force Base, which was in Sacramento, CA.  Mather was first opened (as an airfield) in 1918, which dates this to 1968.  It reads "50 Years of Aviation Mather Air Force Base." The decal itself measures approximately 5 3/4" in diameter, or if measured from the widest part (the part that protrudes on the left side) across, about 6 1/2".  The overall size of the item (including the backing paper) is 7 1/2" x 6 3/4".  Instructions are on the backside.  Backing paper shows some dirt, dimpling and light creasing (this is only the backing paper, not the decal). See scans of front and back for visual confirmation of condition. Decal was made by Fleming Silk Screen, also in Sacramento.