Well known designs for Coro, and much in demand by collectors today, are the double clips which could be combined into one brooch, trademarked as Coro Duette. The mechanism for the Duette was patented in 1931. This mechanism varied in styling for each individual design but how the interlocking components functioned remained essentially unchanged. The Duette brooch and clips styles stayed popular throughout the 1940s. This pin was designed by Gene Verrecchio for Coro and the design was patented in 1941.