Earls straight adapter is manufactured from aluminum and comes with a blue anodized finish. The AN adapter side seals on the flare (cone) not the threads and the NPT side seals on the threads for correct fit. Aeroquip FBM2005 St Alum #6 Flare 3/8in Pipe - Bulk Product Dimension (LxWxH): 3.8x4.75x1.15