From the Tom Crown website:
The Gemini straight mute is our latest and one of our most popular mutes.  Bill Camp, now president of the Tom Crown Mute Co. and I, still owner, foreign secretary, and consultant , decided that we could make a slightly larger, slightly different shaped straight mute,still using the concept of our classic straight mute, and add a new voice to our mute family. As in the development of our other mutes, we started with the idea of what the mute should be. We then had our metal spinner make a number of models of slightly different shapes and sizes. After extensive testing by many trumpeters In our secret sordina cellars we arrived at what is now our Gemini.My main contribution was in the name itself. I thought that a name from the Zodiac might be appropriate. The Taurus mute, no, the Cancer mute, definitely not, the Scorpio mute, no. Then we came to Gemini, the twin, a twin of our classic straight mute.  Many orchestra trumpet sections tried it and it was universally loved. The Chicago Symphony Orchestra, the Boston Symphony Orchestra, the Santa Cecilia Orchestra of Rome and the Paris Opera Orchestra were a few of the many orchestra trumpet sections who adopted the Gemini.Â
The Gemini straight mute is our latest and one of our most popular mutes.  Bill Camp, now president of the Tom Crown Mute Co. and I, still owner, foreign secretary, and consultant , decided that we could make a slightly larger, slightly different shaped straight mute,still using the concept of our classic straight mute, and add a new voice to our mute family. As in the development of our other mutes, we started with the idea of what the mute should be. We then had our metal spinner make a number of models of slightly different shapes and sizes. After extensive testing by many trumpeters In our secret sordina cellars we arrived at what is now our Gemini.My main contribution was in the name itself. I thought that a name from the Zodiac might be appropriate. The Taurus mute, no, the Cancer mute, definitely not, the Scorpio mute, no. Then we came to Gemini, the twin, a twin of our classic straight mute.  Many orchestra trumpet sections tried it and it was universally loved. The Chicago Symphony Orchestra, the Boston Symphony Orchestra, the Santa Cecilia Orchestra of Rome and the Paris Opera Orchestra were a few of the many orchestra trumpet sections who adopted the Gemini.Â