The Color Disc, AccuVac Dissolved Oxygen High Range (0-15 mg/L) is a visual comparator for testing dissolved oxygen levels in water. It provides fast and accurate results, with a range of 0-15 mg/L and a smallest increment of 0.2 mg/L. The test involves filling a sample cell, adding a reagent to an ampule, and comparing the resulting color with a color disc under a light source. The kit is designed for easy, precise readings with a simple, visual method for water quality analysis.