• Includes two 500 ml bottles of pH 7,00 and pH 4,00 calibration solution. • Includes a 30 ml measuring cup for precise dosing. • Calibration liquids with stable values and precision of +/- 0,05 pH. • Suitable for pH meters in hydroponics, aquariums, drinking water, and laboratories. • Large capacity bottle with ergonomic design for easy handling. • Compatible with most electronic pH meters on the market.