Arrowhead PK8004  Replacement Stem for 4-Inch 450 and 480 Series FF Hydrants, 8-Inch Total Length Hose bibs and most products are excluded from the requirements of being "lead free" Arrowhead has residential, retail and commercial products Valves are not intended to be used for potable (drinking) water applications Measure the thin copper tube only and make sure to subtract 2" from your measurement and that is the length you need. The 2" discrepancy is because in the plumbing industry we measure from the wall back and 2" of that thin copper tube falls within the body of the valve.