The OMEGA™ DOH-10 Series is innovative and easy to operate. The DOH-10 Dissolved Oxygen Meter Kit includes Meter, DO Electrode with BNC Connector, NaOH Solution, 3 AAA Batteries, 10 pcs Membrane, Carrying Case, and Calibration Certificate. The -DL Model includes the same plus an 8GB SD Card for Data Logging which allows you to download data from the SD card into an Excel spreadsheet. This allows the user to do further data or graphical analysis without special software. The DOH-10 measures Dissolved Oxygen and has adjustments for altitude and salt. For extended periods of use there is an optional Universal AC Power Adapter which is sold seperately. The DOH-10 has a wide variety of applications from water conditioning, aquariums, and fish hatcheries to food processing, educational and other laboratories.