x x 16-in-1 Water Test Strips x x : Test 16 elements in water, including hardness, chlorine, iron, copper, lead, nitrate, nitrite, fluoride, pH, and more. Provides medical-grade accuracy for home water quality checks. x x Quick and Easy x x : Get reliable results in 3 simple steps��dip for 2 seconds, wait, and compare with the color chart. Saves time and lab costs. x x Versatile Use x x : Suitable for drinking water, pools, ponds, aquariums, spas, and industrial wastewater. Complies with EPA standards for lab, school, or home use. x x Storage Tips x x : 1. Seal tightly after use to maintain effectiveness. 2. Store in a cool, dry place away from light and moisture. 3. Keep desiccant pack inside. 4. Use within 90 days of opening; shelf life is 2 years from manufacture date. x x Package Includes x x : 1 set of fluoride test strips. x Note: Colors may vary slightly due to lighting or display settings. Measurement tolerance: 1-3cm. x Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.