Features: Water tester with precise color coordination and high sensitivity, use professional for health drinking water test strips to test water quality standards. A pack of test strips includes 50 pool test strips and seals, 5 moisture-proof packages to ensure long-term storage. Soak the stripe- 2 seconds- for underwater, keep about 15 in the air, and then match the color of the strip- to the color on the back of the bottle, which takes about 17 seconds. The test strips are suitable for drinking water, aquarium-, swimming pool and spa-, industrial water, pond, hot spring water testing. Easy to carry: size about 1.46x3.94inch. Specifications: Material: Paper Size: Approx.37x50mm/1.46x3.94inch Note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the differences between different monitors, the picture may not reflect the actual color of the item. Package includes: 50x Water Test Strips