Mastercool 52733 Salt Solution Bottle 33% (dark brown bottle) is used for calibration of the Mastercool 52230 Pen Type Hygrometer and the Mastercool 52233 Digital Psychrometer.

Warning: This product may expose you to chemicals including lead which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov