407510 is a Heavy Duty Dissolved Oxygen Meter with PC interface. Recall Min, Max and Average readings. Featuring Data Hold and a Built-in RS-232 PC serial interface with optional data acquisition software and data logger. Auto power off saves battery life. DO measurements from 0 to 20.0 mg/L. Complete with 0.8" (20mm) diameter probe on 13ft (4m) cable, 5 membranes, rubber holster, 9V battery and hard case.