For choke tubes that do not have notches, or even those that do, the internally expanding wrench made by Carlson (sold by Cabelas) is excellent. Works on all types of choke tubes and I have not found one I couldn't loosen with it. FWIW the Briley thin wall chokes I have work well with this wrench but mine do have notches for a Briley speed wrench as well. I like the Carlson wrench better than other wrenches when I shoot sporting clays.
Thanks
Z