Flare Reducing Union 　 Part No. Ref. No. Description 506-0604 06-04 3/8" O.D. Tube x 1/4" O.D. Tube 506-0806 08-06 1/2" O.D. Tube x 3/8" O.D. Tube 506-1008 10-08 5/8" O.D. Tube x 1/2" O.D. Tube