The basic tool for measuring pH and chlorine quickly and accurately is the most commonly used water sanitizer to kill bacteria, algae and microorganisms. The perfect tool for maintaining a pool or spa within a safe chlorine and pH range, without chemicals or the guesswork.An electric tester for ph and chlorine (Cl2) levels for routine monitoring of levels of ph and chlorine in swimming pools, spas and various water sources. When chlorine and pH are due to shock, it can cause diabetes and ear and skin infection. Good chlorine and good pH keep bad bacteria away: if the pH is too high, the electricity lost by the chlorine will be drained. When a large amount of nitrogen (feces, urine, sunscreen or sweat) or other organic matter enters the pool, chlorine is also consumed. This is why it is best to test chlorine and pH constantly - this can change daily depending on how the pool is used. Keeping your pH in the correct range is important for keeping the surface of equipment and pools clean. Your chlorine dissolves faster in low pH. A high ph value will invalidate the chlorine. This electric meter saves you time and money. Noticed : Because if the product with battery, the customs will not pass, so the product does not include the battery, hope you can understand, thank you. Attention : Recommended chlorine content for pools and spas 1.2 1.7 ppm Recommended pH for pools and spas are 7.2 7.8 ph Product: Round Chlorine Tester Specification: Material: plastic Weight: 296g Food: 1 * 1.5V AA battery (not included) Note: 1. Please do not immerse the probe in any liquid other than pool or spa water.2. Please turn the switch to the closed position when not in use.3. Please store the tester in a cool, dry place. Product : Square Chlorine Tester Features:1. Made of premium plastic shell, durable and sturdy.2. Easy to use, no more chemicals needed.3. A handy tool to test water pH and chlorine level for swimming pool and spa.4. The large screen displays the test result on pH and chlorine level for easy and accurate reading.5. Lightweight and compact, easy to carry. With a hole for convenient hanging. Please do not immerse the probe in any liquid other than pool or spa water.2. Please turn the switch to the closed position when not in use.3. Please store the tester in a cool, dry place.1*Chlorine Meter2*Manual