HANNA general purpose cleaning solution for use with pH and ORP electrode that can be used for a variety of applications. pH and ORP electrodes become dirty with use and can produce inaccurate results. Use HANNA general purpose pH electrode Cleaning Solution to prolong the life of your electrode and ensure accurate readings.HANNA Cleaning Solution for Electrodes+ specially formulated for cleaning pH and ORP electrodes+ clearly marked expiration date and lot number for traceability+ air-tight seal to ensure the quality of the solution