For maximum buoyancy in your Boobie flies. These pre-made eyes make tying your boobies very easy. The eyes are available in 2 sizes, Medium and Small. Boobie flies are flies with buoyancy in the "eyes", which because the front part of the fly floats while the body sings, it imitates everything from something that is about to hatch or some small fish that eats from the surface. Here, only your imagination sets the limits of what you can tie. Boobie flies can also be used with a sinker line to fish the fly "upside down", then the fly is pulled down on each pull and then floats up on each pause.