This item is a pinback button or pin probably from the 1930's made by Greenduck Co. of Chicago, also known later as Green Duck.

This pin is one of a series that Greenduck made featuring various famous aircraft of the early 20th century. This one features the Hawker Nimrod biplane and is number 4 in the airplane series. Inside the back is the Greenduck Co, Chicago emblem. The pin is a pink color with a picture of the airplane. It is about 0.8" in diameter. This has a lot of wear. I have others of this series I am also listing.

Purchase of additional pinback buttons from me  will add little or nothing to the shipping costs provided you let me send you a combined invoice before you pay.