The Hanna Instruments 70300M is an electrode storage solution for Hanna pH and ORP electrodes. It includes one 230 mL bottle of colorless, odorless, soluble liquid solution. Electrode storage solutions help maintain the moisture of the glass bulb and the junction of the electrode, which in turn helps to reduce clogging and extend the life of the device.

Hanna Instruments manufactures analytical instrumentation and supplies, including pH meters, electrodes, chemical reagents, and buffer solutions. The company, founded in 1978 and headquartered in Woonsocket, RI, meets International Organization for Standardization (ISO) 9001 standards.