Oakton - Combine measurement capabilities of three testers in one convenient pocket-sized unit, and can do up to 5 point pH calibration with NIST or USA auto-buffer recognition. Conductivity, TDS, and salinity feature auto-ranging based on the concentration of your sample. Great for water, laboratory or plant use, these Multiparameter Testers feature single-junction pH electrodes for longer life and wider range of sample compatibility. The units Pin-style conductivity sensors feature stainless steel electrodes for chemical resistance and durability and are replaceable sensor module. Some of the advanced features include auto-shutoff, user-adjustable temperature coefficient, self-adjusting TDS and salinity factor, and a low-battery indicator.