**16-in-1 Water Test Strips**: 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. **Quick & Easy**: Get reliable results in 3 simple steps��dip for 2 seconds, wait, and compare with the color chart. Saves time and lab costs. **Versatile Use**: Suitable for drinking water, pools, ponds, aquariums, spas, and industrial wastewater. Complies with EPA standards for lab, school, or home use. **Storage Tips**: 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. **Package Includes**: 1 set of fluoride test strips. *Note: Colors may vary slightly due to lighting or display settings. Measurement tolerance: +/- 1-3cm.* 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.