HI7004M is a premium quality pH 4.01 calibration solution. Hanna calibration buffers have the lot number and expiration date clearly marked on the label and are air tight with a tamper-proof seal to ensure the quality of the solution. Hanna's line of calibration buffers have been specially formulated to have an expiration of 5 years from the date of manufacture for an unopened bottle.
Accuracy of +/- 0.01 pH @ 25°C
Temperature chart of the actual pH value at various temperatures printed on each bottle
Air-tight seal to ensure the quality of the solution