Anderson Metals Brass Tube Fitting, Union, 5/8" x 5/8" Compression Union for connecting and disconnecting two tubes more easily than with a coupling Compression tube connections on both ends Brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability Operating temperature range of -65 to +250 degrees F Three piece construction - nut, sleeve and body These fittings contain lead and are not allowed by federal law to be installed for potable water use in the U.S.A. and its territories.