pH Meter Tester Buffer Powder Calibration Packs (2) - 1， pH 4.00 and 1， pH 6.86<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Great for initial calibration of pH meters and testers</li><li>Calibration buffer powder dissolves easily in distilled water</li><li>ENSURE ACCURACY after long term storage</li><li>2 packs included - 1， pH 4.00 and 1， pH 6.86</li></ul></div><img src="http://ecx.images-amazon.com/images/I/31mYQdS033L.jpg" noproxy>