The FieldScout TCM500 NDVI Color Meter measures reflected light from approximately a 3" (7.6cm) diameter section of turfgrass. Connects to any GPS receiver that has serial output options. Equipped with internal data logger and RS-232 port. Records over 3,000 measurements (1,350 with added GPS/DGPS option). Configure and download your data with the FREE FieldScout Software available on our website. If you have a SpecConnect subscription, you can then upload the data to utilize available reporting features. Includes hard carrying case, TCM500 T-Handle, USB to 3.5mm Stereo Plug Adapter (Item #3661U) and batteries.