This LaMotte ColorQ Pool 4 measures DPD Free Chlorine (0 to 10.00 ppm) and Bromine (0 to 22.0 ppm) - note Bromine uses same Free Chlorine reagents. In additional, the unit can also measure DPD Total Chlorine (0 to 10.00 ppm), Bromine (0 to 22.0 ppm), pH (6.5 to 8.5 pH), Total Alkalinity (0 to 250 ppm), Calcium Hardness (0 to 700 ppm), and Cyanuric Acid with optional reagents sold separately. The compact photometer is easy to use and utilizes economical liquid reagents, good for 144 tests per reagent type.