Nynelly 20 Pack pH Meter Buffer Calibration Solution Powder for Precisely Calibrate Meter, Tester Packets, 6.86/4.01

【High accuracy】pH buffer calibration solution powder accuracy is ±0.01pH. Suitable with most of electronic pH meter ph tester. 【20 pack pH calibration solution powder】10 packets of pH 4.01 solution powder, 10 packets of pH 6.86 solution powder. Cost-effective and flexible in use, to meet your various needs. 【Easy to use】Mix pH buffer powder with 250ML distilled water, put the pH meter into the solution, stir gently and wait for a few seconds to get the result. pH calibration powder allows you to test the pH of swimming pools, aquariums, water quickly and accurately with a pH meter. 【High quality】pH calibration powder is produced with quality material under strict conditions. Sealed by durable moisture-proof individual packet to maintain freshness until use. 【Easy to carry and store】Small size, easy to carry and store, very convenient. CAUTION: Not a drinkable solution!