KOUL tools Fitting Fixers are used to repair the conical surface of a fitting and restore the seal by utilizing a lapping head and guide (along with the use of a a drill to spin it) to repair leaky fittings. Fitting Fixers are offered in your choice of a 4-pack kit or in single 3/16", 1/4", 3/8" or 1/2" sizes. To repair, simply screw the damaged fitting into a guide, then connect the lapping head to a drill and intermittently spin it several times. After spinning, inspect the surface for any imperfections, and repeat the lapping process until a clean surface is achieved.