Starrett 42 Lock-Joint Hermaphrodite Calipers feature an adjustable point, locking joint and fine-adjustment feature for close measurements. After the legs have been set to approximate size and joint locked, the final adjustment is made by a few turns of the knurled adjusting nut. Starrett Hermaphrodite Calipers are used in layout work for locating and testing centers, laying off distances from an edge, and more. Machinists and Toolmakers have a wide selection from which to choose. Caliper size and capacity is 6". 6" (150mm), Lock-Joint, Fine-Adjustment.