The Oakton 00653-04 pH/ORP 1-pint (550mL) electrode storage solution is used to store electrodes for accuracy in testing liquids in lab and field applications. This liquid solution is to keep the probe bulb moist and in proper working condition for quick readings. It comes in PEGC-bottle packaging to improve shelf-life, and is manufactured according to the APHA and ASTM formulation for more accurate readings. The 00653-04 storage solution containing pepsin is soluble and comes in a 1-pint (500-mL) bottle. It is used with electrodes (sold separately). A storage solution is used to store electrodes and keep bulbs moist to extend the life of a probe, increase the speed of response, and obtain more accurate readings. Storage solutions are used in water treatment, hydroponics, aquaculture, and in various types of manufacturing. Oakton Instruments manufactures an array of scientific instruments for research, industrial, and educational uses. Since 1991, Oakton has distributed a wide variety of instruments such as meters, electrodes, and transmitters. Oakton is based in Vernon Hills, IL, and has facilities in Europe, Asia, and China.