Fish Skull Articulated Shanks are great; no more cutting the hook off the shank to extend your flies and no more tying in dacron or nylon to achieve the extra action seen with articulated flies. Tying articulated streamers just got easier. The wire diameter of the Articulated Shank is roughly the same as a typical #4 or #2 streamer hook. It needs to be this diameter in order to fit through the eye of the hook you are articulating. So by default, the Articulated Shank is intended for streamers using hook sizes from about a #4 hook upwards. Experiment with your hooks as there is no industry standardization and hook eye sizes will vary between hook makes, models and sizes.