Extech DO610 ExStik II DO/pH/Conductivity Kit Measures dissolved oxygen, pH, conductivity, TDS, salinity and temperature Includes EC500 pH/conductivity meter with combination high accuracy multi-ranging conductivity sensor Includes DO600 dissolved oxygen meter with electrode, replacement membrane cap, electrolyte, and polishing paper Complete with 3 calibration standards, 3 pH buffer pouches plus rinse solution, 3 plastic cups, batteries and carrying case