The Starrett AccuBore is a high-quality, trigger-activated, three-point contact bore gaging system with extended range. Its convenient single-hand operation provides speed and control. It features a large, easy-to-read digital display, and a mechanically-driven parallel anvil, establishing a more true alignment to the axis of the bore that provides consistent pressure, resulting in more accurate readings than models with spring-driven contacts. Speed and convenience are further enhanced by the repositionable AccuBore indicator, which may be swiveled and rotated for left, right hand or even vertical viewing. The gage also features a set of "go/no go" lights that quickly indicate whether a bore measurement is within a preset tolerance window. SET, Pistol Grip, 3/4 - 2" (20-50mm) Range window.