Abstract: An improved device and system to precisely locate a point on a workpiece. The device and system is also used to precisely position a work tool with respect to the workpiece. The device incorporates a probe end and a contact end. The contact end has a bottom facing contact surface that is smooth and planar within an exacting tolerance. The probe end may be cylindrical or spherical with a precise diameter B and a rear facing portion. The contact end is slideably positioned with its bottom facing contact surface firmly against a reference surface of the workpiece. The device is positioned in order that the rear facing portion of the probe end is firmly in contact with a second surface of the workpiece. The extensions of the plane of the second surface of the workpiece and the plane of the reference surface form an intersection, either real or imaginary. The plane of the second surface forms an angle with the perpendicular to the reference surface plane at the intersection.