These combined form thermo-hydrometers offer the additional convenience of an enclosed thermometer with a temperature scale of 0/150°f, and measure specific gravity / relative density g/cm3 of a variety of liquids in various ranges from 0.600 to 2.000. conform to the accuracy requirements for astm thermo-hydrometers commonly used in industries such as food and beverage, chemical, pharmacology, transportation, refrigeration and more 381mm 15 long lead free ballast and glass temperature standardization: 60°f 15°c thermometer contains mercury-free blue spirit organic liquid fill individually serialized hand inspected by our u.s. Quality team packaged with a multi-language english, french, german, italian, portuguese, and spanish statement of accuracy indicating accuracy traceable to nist note : combined form hydrometers should be stored in a clean, dry, safe place, and should not be subjected to extreme temperatures. Enclosed thermometers should be used as a general reference only. For temperature critical applications, a calibrated standard thermometer is recommended.