Hydrometer, DURAC, 19/31, API Formerly Part# 50020
HB Instruments Hydrometer, API, 19 to 31° Range, 0.2 Division, 166mm L, 0.2° Accuracy, 60°F Standardizing Temperature, Plain Form, Individually Serialized, Feature Metal Ballast, Include Multi-language Statement of Accuracy, Tested and Calibrated in Exclusive Triple Accredited/Registered ISO/IEC 17025:2005, A2LA Accredited Laboratory Against Equipment whose Calibration is Traceable to NIST and DAkkS - BEL