HI5036-050 is a quick calibration solution for use with Hanna's GroLine pH and/or EC/TDS meters. Using the Quick Cal function found in compatible meters allows for a single point calibration for pH and/or conductivity sensors. Each bottle has the lot number and expiration date. Hanna's line of calibration solutions have been specially formulated to have an expiration of 5 years from the date of manufacture for an unopened bottle. The HI5036-050 is for 500 mL of calibration solution