2 in 1 Water Quality Tester---a multifunctional water quality tester which can test chlorine gas or PH value in water via switch button.Large Screen --- Large screen displays clearer and faster readings, which can intuitively reflect the water quality.Sturdy and Durable --- The shell is made of High quality thick plastic, strong and wear resistant, and can be used for a long time.Features --- Light weight, small size, easy to carry. With holes for easy hanging.Advantages --- Easy to use, no chemicals required. Can be used to test water quality in swimming pools, spas, etc.Power supply: 1 AA 1.5V battery (not included)Recommended chlorine levels for swimming pools and spas: 1.2 ~ 1.7 ppmpH recommended for swimming pools and spas: 7.2 ~ 7.8 pHPackage includes1 x Water Quality TesterCONSTRUCTION INSTRUCTIONS 'ELECTRIC TESTERTo prolong the life of your Pool Checker PC-102 and ensure accurate results, be sure to:Keep the switch in the OFF position (all the way to "PH") when not in use.Store in a cool, dry place away from sunlight.DO NOT immerse the probe in any liquid other than pool or spa water.Check battery freshness regularly - unit requires 1 x 1"AA" alkaline battery .5 volts.CHLORINE CALIBRATION SET POINT:Before using your Electrotester (ET) for the first time, you should need to adjust (calibrate) AND to match your pool or spa water with the following sequence:1. Test your pool or spa water using a conventional liquid test kit2. Record the level of chlorine reading you will need (example: 1.5 ppm)3. No adjustment is required for pHFIND YOUR ADJUSTMENT POINT ANDA. Insert a 1.5 volt AA battery into the compartment inside the handle (positive side up).B. Hold the ET in one hand and the probe in the other.C. Insert the cleaned metal probes into the water up to the black band.D. Stir the water slightly with the probe.E. With the probe still in the water, turn the wheel on the face of the tester all the way to the left towards "CL". Slowly turn the wheel to the right until the needle matches the chlorine level you recorded with the liquid tester convention (example 1.5)F. Remove the probes from the water without touching the wheel.