The pinback button measures 7/8'' wide. It appears to be in good used condition with some light wear as pictured. Below here, for reference, is some additional information about the Uncle Don radio program:
From Wikipedia, the free encyclopedia
Uncle Don was a children's radio program which aired on WOR radio from 1928 to 1947. The host was Uncle Don Carney, a former vaudeville performer (real name Howard Rice, 1897 - 1954). The half hour program was broadcast daily, five or six days a week.
Debuting September 1928, it was the most popular children's show of that era due to the powerful 50,000 watt range of New York's WOR station. Carney sang, played the piano, told stories and introduced a variety of features: the "Earnest Savers Club" which encouraged setting up accounts at the Greenwich Savings Bank; a "Healthy Child Contest"; a "Talent Quest" that provided screen tests for winners. Each program began with Uncle Don arriving in the imaginary autogyro he called his "puddle-jumper."
Star: Don Carney
Sponsors: Maltex Cereal, others, sustaining (none)
Network: Local (WOR), Mutual
Aired: 1928 - 1949
Type of Show: Juvenile Variety