The SPAD Plus Chlorophyll Meter with Data Logger instantly measures chlorophyll content or "greenness" of your plants to reduce the risk of yield limiting deficiencies or costly overfertilizing. Clamp the meter over leafy tissue and receive an indexed chlorophyll content reading in less than 2 seconds. Connects to any GPS receiver that has a serial output options. Equipped with internal data logger and RS-232 port. Records 4,096 measurements (1,488 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, USB to 3.5mm Stereo Plug Adapter (Item #3661U) and batteries.