This quality AN O-Ring to AN O-Ring  adapter / reducer is precision made from billet aluminum and anodized black for seamless use in your fuel system. This nifty fitting takes the common 8AN ORB sized opening, like a fuel rail, or Regulator, down to a 6AN ORB O-ring female boss.  This unique adapter is one of a kind, and very handy with aftermarket ORB fuel rails, and push lock OE type connections. 

Common application would be reducing your Hemi or LS fuel rails to accept Common 3/8' or 5/16' Male Quick connects such as BPP6ORB38 or BPP6ORB516.