1.75". This button has about 30% red paint off the metal backing plus an extremely damaged/rusted collet which actually has a sliver .75" long missing. The celluloid remains relatively stain free with just some small marks around the front outer edge and a tiny dot center right. Curl of the button has copyright symbol and reads "Sue Jean Lee/Class Of 1970/Princeton Univ." Front of the button with stylized peace symbol reads "1970/Together For Peace." Lee, who died in 2011, was one of the first female graduates of Princeton and the first women to be in the cast of Triangle Club. This button was a personal issue very limited in distribution. Only example we've seen. Given the condition of the reverse we can't call this much better than Fair but the front still displays well.