The Extech 407510 is a professional dissolved oxygen (DO) meter designed for water quality analysis in environmental, aquaculture, wastewater, and laboratory applications. Featuring a dual large 1.4” LCD display for simultaneous DO and temperature readings, automatic temperature compensation, and built-in RS-232 interface, it supports real-time data logging and PC connectivity. Includes polarographic DO probe with 13ft cable, replacement membranes, fill solution, holster, and hard case.