reducing quick couplings. Size: couplings 1/4"-4". Standard:ANSI B16.11. End type:THD,SW,BW. Certificate:ISO9001 and CE Features:1 ... quick couplings.2.Size: couplings NPS 1/4"-4".3.Standard:ANSI B16.11.4.Mateiral:carbon steel,stainless steel,A105 ... ,A403,A420 etc.5.End type:THD,SW,BW.all the type of reducing quick couplings used depends on ...