The invention discloses differing embodiments of calibration apparatus, and methods of use. In one embodiment, the calibration apparatus may be used to calibrate a tool, positioning system, robot, machine, or device. The calibration apparatus may include a first member adapted to be attached to a tool, positioning system, robot, machine, or device, and two or more reflectors attached to the first member. The reflectors may be adapted to reflect one or more laser beams emitted from a laser tracker system. In such manner, a laser tracker system may be used to determine spatial X, Y, and Z coordinates of the reflectors, and/or to determine angular orientation of the first member. Using the spatial X, Y, and Z coordinate and angular orientation data, a tool, positioning system, robot, machine, or device may be calibrated.