The CON-TROL-CURETM PH CALIBRATION SOLUTIONS allow you to recalibrate your existing pH Meter. Either calibrate it around a neutral 7pH level, around an acidic 4pH level, or around a alkaline 7pH level. This solution comes standard in some of our pH Meter kits, but refills are available individually. Sold in 1 pint container or 1 quart container.