Gretsch Horseshoe from Diamond Truss Rod Cover. It features 11 round, 3mm, brilliant, lab-created Diamonds (moissanite) crafted in the shape of the famous Gretsch Horseshoe. This will fit the Electromatic series with no modifications. The Streamliner series will require drilling new holes but should cover up the existing holes. I am unsure about the Pro series, but you are welcome to research the model # “Gretsch 006-0898-000 Falcon/Penguin Truss Rod Cover – Black” made in Japan.