This reagent set contains Orbeco-Hellige's Powder Pack™ and Tube Test Reagents. Powder Pack Reagents are pre-measured, unit dose reagents that have been formulated for use in Orbeco-Hellige's Aqua Comparator Test Kits, the SC450 Single Parameter Colorimeter Series, MC500 Multi-Parameter Colorimeter, and the SP600 Spectophotometer. These easy-to-use chemistries offer an extended shelf life and serve as a direct replacement to Hach® reagents. They can also be used in Hach® instruments. Why pay more for the same results? Orbeco-Hellige will stand behind the comparability of results.