These light meters offer wide measuring range up to 400,000 lux (40,000 fc), and provide cosine- and color-corrected capabilities. Meters feature a precision silicon photo diode and spectral response filter, and include relative mode indicating a change in light levels. Datalogging model (50512-32) automatically stores up to 16,000 readings or manually stores/recalls up to 99 readings. Whats Included: light sensor with 3-ft (1-m) cable and protective cover, Windows? compatible software with USB cable, hard carrying case, and one 9 V battery. Datalogging model allows the automatic or manual storing/recall of readings