ARP’s Rod Bolt Stretch Gauges are highly recommend for when installing rod bolts and other fasteners, where it is possible to measure the length of the bolt after tightening. These gauges offer the most accurate way to determine the correct pre-load in the rod bolt. These highly accurate stretch gauges come with a dial indicator that reads in increments of .0005”. Featured are extra heavy springs for consistent repetition and includes a heavy-duty, insulated plastic carrying case for protection.