Pack of 50 disks for use with the LaMotte Mobile WaterLink Spin Lab. Each disk tests for the following factors: Fr Chlorine: 0 to 15.0 ppm; Total Chlorine: 0 to 15.0 ppm; Bromine: 0 to 33.0 ppm; pH: 6.4 to 8.6; Calcium Hardness: 0 to 800 ppm; Total Alkalinity: 0 to 250 ppm; Cyanuric Acid: 5 to 150 ppm; Copper: 0 to 3.0 ppm; Iron: 0 to 3.0 ppm; Salt: 0 to 5000 ppm; Phosphate: 0 to 2000 ppb.