Microprocessor assures maximum accuracy plus special functions. Super large 1.4 in. (1999 count) LCD display. Percent displays differential from reference point. ZERO Re-Calibration. Utilizes precision photo diode and color correction filter. Cosine and color corrected measurements. Plus/minus 4 percent accuracy is enhanced by selecting lighting type (Tungsten/Daylight, Fluorescent, Sodium, Mercury). Record/Recall MIN, MAX and AVG readings. Data Hold plus Auto shut off. Built-in RS232 serial interface, optional software. Dimensions: 7 x 2.9 x 1.3 in. (178 x 74 x 33mm). Weight: 1.6lbs. (726g). Complete with 9V battery and protective holster. Optional Windows Data Acquisition Software and serial cable enable user to display and capture readings on a PC, and set time intervals and alarms. Optional battery operated Datalogger module stores over 8000 readings for later transfer to a PC.