Model 6394 flow control is engineered to provide a proper drinking stream height at pressures varying from 30 - 90 psi (2.1 - 6.2 bar). It is important that the flow control selected match the bubbler orifice. Lead-free Tellurium copper coupling with .4 gpm (1.5 L) flow rate. Includes cone, friction washers and slip joint nut. 9/16" (1.4 cm) OD inlet x 1/2" NPT(F) outlet.