LNIB,This filter is for my c-11,I also have a ThousandOaks camera adapter
for the unit. I am in the process of buying a DayStar T-scanner and have to sell my ThousandOaks H-Alpha Solar Prominance Filter to help finance the DayStar. This filter is in excellent condition and works very well. I will sell the filter and camera adapter for $450.00. I will pay S/H. Thanks for looking.