This 407026 Heavy Duty Light Meter has four illumination type settings for improved accuracy (tungsten/daylight, fluorescent, sodium, and mercury). Additional features include Data Hold, Min/Max/Average, Auto power off, and a percentage differential reading from a reference point. Built-in RS-232 port with optional Data Acquisition Software and Datalogger. Includes a 9V battery, light sensor with a 45" (1.1m) cord, protective cover, and holster with stand.