Extech EC-12880-P 12880uS Conductivity Standard (2 bottles). Pint size bottles with pre-made 12880??S conductivity calibration solution.
Proposition 65 Warning for California Residents: This product can expose you to chemicals including Benzene, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.