High cost performance, a box of 50 test rods, can test multiple data at the same time High-end plastic plastic bottle packaging, waterproof and moisture-proof Used for water quality test of swimming pool or hot spring pool Easy to operate and easy to carry 4-In-1 water quality: Residual Chlorine PH Value Alkalinity Hardness Specification: Quantity: 50 pieces/bottle Storage method: dry and ventilated storage is recommended Applicable to: used for water quality testing of swimming pools or hot spring pools Reminder: It is recommended to use it at room temperature, otherwise it will cause inaccurate results Instructions: 1. Immerse the test strip in water for 2s 2. Stay in the air for about 15 seconds 3. Compare the test strip with the color chart bottle Package Includes: 1 bottle water quality test paper (50 pieces) 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.