I just received the CORS Fortune coil that I ordered to complete my coil selection for my T2s. I now have a broad selection of coils to cover most metal detecting scenarios. So far, I have the Teknetics 5" round DD, the Teknetics 11" oblong DD, the Teknetics 15" round DD, the CORS Fortune 5.5"x9.5" DD and the CORS Strike 12"x13" DD coils. What other coils do you T2 people keep in your arsenal that you find useful that you use often?