Features: 1. Easy to use. Take a test strip and immerse it in the swimming pool water for about 2 seconds, remove it and lay it flat, after 15 seconds, compare the reading with the color on bottle. 2. 3-in-1 function(more functions optional), each test paper can test Chlorine, PH value and Alkalinity simultaneously. 3. Total Chlorine test range: 0-1-3-5-10. 4. PH test range: 6.8-7.2-7.4-7.6-8.0-8.4. 5. Total Alkalinity test range: 0-40-80-120-180-240. Notice: Actual colors may vary from that of the image due to computer settings. Please allow minor deviations due to manual measurement. Affordable 50 Strips: This Water Chemistry Test Kit Contains 50 Test Strips. Enough To Balance Your Pool, Hot Tub, Spa And Other Water Tests. Testing At Least Twice A Week Is Recommended To Keep Your Pool Clean And Safe. Simple And Quick Test: Just Immerse In Water For 1 Second, Then Take It Out, Hold The Test Strip Horizontally For 15 Seconds, Compare With The Color Chart On The Bottle, You Can Get Clear And Accurate Water Quality Results. Total Chlorine Test Range: 0-1-3-5-10. PH Test Range: 6.8-7.2-7.4-7.6-8.0-8.4. Tips For Accurate Results: Keep Wet Fingers Away From The Test Strip. Read In Natural Light For Best Results.