1. Wide pH range: These pH meter test strips have a wide range of 1 14, making them suitable for testing substances with different acidity and alkalinity. 2. Clear acid or alkaline display: The color changing paper accurately measures the acid or alkali content. An acidic substance is indicated by a color change of 4 6, while alkalinity is indicated by a color change of 8. 3. Easy to use: Press the test strip on the object or liquid to be tested and compare the color change with the included color chart. The results are achieved within half a second, allowing for quick and convenient testing. 4. Compact and portable: With dimensions of approximately 45mm x 7mm (L x W), these test strips are compact and easy to carry. You can easily test the acidity of your subject, whether at home, in the laboratory, or elsewhere.