This straight adapter makes it easy to plumb your fuel system with 6AN hose. The male 9/16-24 straight thread fits Holley Single Feed 600-660 Series, 4010/4011 Series, all Holley two-barrel with 9/16-24 thread, and all Demon carburetors. The other end is a 6AN male fitting to accept a standard hose end. Blue anodized aluminum. Sold individually.