1.75" with 1969 syndicate copyright on the curl along with the name of Charles Schulz and name of issuer "Simon Simple." Button is one of the scarcest and best designs in the series picturing Peanuts characters. Snoopy is depicted on cratered moon surface with stars in the heavens above. He wears a space helmet and his cartoon thought balloon states "I'm On The Moon!" Button has 3/16" spot of air under the cello on the top edge of the balloon, as made, but is otherwise Mint. This is one of five examples we've offered in five decades. Typically, if no damage, $200.+, but our Auction #200 mint example realized $460. The air spot shows slightly, but rest of the piece is glossy Mint. A conservative opening.