The MI512-25 Low-Range Phosphate liquid reagent kit includes high-quality reagents that are ready-to-use with Milwaukee's MW12 Low-Range Phosphate Tester. The reagents and meter use the Adaptation of the Ascorbic Acid Method. Simply add the reagent to the sample, wait for the reaction to take place and the photometer determines the concentration based on the color. The reagents are designed for use with samples that have an expected range of 0.00 to 2.50 ppm (mg/L) PO4.