11/16” with reverse initials of maker Whitehead & Hoag. As the war ended approximately 132,000 project members received one of these pins. Our previous lot #782 in the Sterling form went to those serving longer than one year while the others received this brass version. Project participants ranged across the country from areas such as Columbia University to Clinton Engineering Works in Oak Ridge, Tennessee to those in New Mexico. Front of this one has been lightly cleaned compared to the brass tone on the reverse but it also displays essentially Mint.