This 787 Universal Dial Indicator Set has a spiral type mechanism of unusually rugged construction for the more severe applications around machinery and for general tool work. The indicator can be supplied in inches as well as in metrics. The hole attachment used in conjunction with any standard dial indictor make it possible to test inside of holes and many other surfaces that can not be reached with the regular indicator spindle. The each attachment has a 0.375” diameter hole to fit all indicators and are securely clamped to the indicator stem by means of a knurled screw. The ball end of the swivel arm, which contacts the work, is 1/ 8 “diameter and the body of the arm is 3 / 16” diameter.