Hy-Lok Sure Ring Is especially useful when you Install Hy-Lok fittings in a small space such as in a cabinet where it is practically impossible to apply the standard installation procedures. (i.e., 1 1/4 turns or 3/4 turns from finger tight) It ensures sufficient tightening and protects over-tightening, For installation, insert Sure Ring between the nut and the body before assembly, and then tighten the nut until being blocked by the sure ring.