Radium Engineering 5/16" barb to 6AN bulkhead fitting is a green anodized aluminum bulkhead fitting used on Radium fuel surge tanks after 2014. The barb measures 8.5mm and the fitting requires a 9/16-18 threaded hole with a chamfer in the mating part for proper sealing. It provides a sealed feed-through and is intended for use where a bulkhead connection from hose to AN plumbing is needed.
Radium Engineering 5/16in Barb to 6AN Bulkhead Fitting