Calibration accuracy has not been independently verified. Tested and working. Unit powers on, completes its startup cycle, and zeros properly in clean air. Sensor was tested with isopropyl alcohol vapor and responded properly, then returned to 0 ppm after the vapor was removed. All buttons, display, backlight, audible indication, and adjustable tick rate were tested and are working properly. Flexible probe bends and holds position properly. Includes detector and carrying case only.