H-B Instrument B61809-0100 Plain-form Glass Hydrometer, 0 to 26.5% Salt By Weight/0.5% Div DURAC Salt Brine plain form hydrometer has a range of 0 to 26.5 Individually serialized; features metal ballast Graduated in percent by weight of sodium chloride Temperature of standardization 60F/60F Tested and calibrated in an exclusive triple accredited/registered ISO/IEC 17025:2005, A2LA accredited laboratory against equipment whose calibration is traceable to NIST and DKD/PTB