An apparatus comprises an outer shell, a gauge ring, and a spring. The gauge ring is configured to rotate to a first position as a nut passes through an opening of the outer shell and contacts a bottom surface of the gauge ring, the first position permitting the nut to pass through the gauge ring and into a socket by aligning one or more gauge ring lobe slits with one or more outer shell lobe slits and one or more deformable lobes of the nut. The spring is configured to rotate the gauge ring to the second position after the nut passes through the gauge ring and into the socket, the second position preventing the nut from exiting the socket by preventing alignment of the one or more gauge ring lobe slits with the one or more outer shell lobe slits.