ORP Calibration Buffer Powder 256mV Redox Potential Analyzer Test Pen M89BOOTDTY Calibration BufferORP Calibration Pen Powder 256mV Redox Potential Analyzer Test Pen Calibration Liquid BufferORP Correction Powder Buffer Powder is a newly developed, convenient to transport and carry, solve the problem of inconvenience and expensive transportation of ORP correction liquid, and make ORP correction more convenient and easier. Add 50ml distilled water or purified water into the powder packAbout this product:This powder can can be configured with ORP 256mv calibration liquidNote: the product does not include the test pen in the picture, it is a mold to show the function of the powderPackage Included:1 x ORP Buffer Calibration Powder