VIVOSUN 18-Pack pH Meter Buffer Solution Powder, pH 6.86/4.00/9.18, pH Buffer Powder for Precise and Easy pH Tester Calibration

["High Accuracy: These high-purity buffer powders ensure precise pH calibration with ±0.01 pH accuracy at 25°C/77°F; They keep your pH testers sharp and reliable for consistent results","High Stability: These premium buffer powders maintain accurate pH values of 6.86, 4.00, and 9.18, even after long-term storage, saving you from repeated purchases for pH calibration","Individual Packets: Includes 6 packets of pH 4.00 solution powder, 6 packets of pH 6.86 solution powder, and 6 packets of pH 9.18 solution powder; Each packet is individually sealed to ensure freshness and accuracy, making them easy to carry and store","Quick Dissolution: These pre-measured pH buffer solution powders dissolve quickly, streamlining the calibration process; They contain no harmful substances, ensuring safe handling","Simple to Use: Compatible with any pH tester and probe; Just empty a packet into a clean glass beaker, add 250ml deionized or distilled water, stir gently until dissolved, and you're ready for calibration"]