Fly Fishing Patents : Fishing line accessory systems, methods, and apparatuses

Fishing line accessory systems, methods, and apparatuses for securing strike indicators, bobbers, floats, weights, and other accessories to a fishing line include a primary coupling component and a secondary threaded coupling component. At least one of the coupling components has a gap defined therein. At least one of the coupling components has at least one fishing accessory connected or connectable thereto. The secondary coupling component is matable with the primary coupling component such that the gap is obstructed when the coupling components are in a mating relationship. A fishing line that is captured by the coupling components in an adjustably secure relationship can be adjusted without completely disengaging the threaded coupling components.

I'm guessing that this is the Airlock Indicator patent.