Apollo Command/Service Module Oxygen System Purge Line Connection Port, measuring approximately 7" x 1.75" x 1.75", marked at center with Fairchild Hiller/Stratos-Western part information: "Coupling, Fill, Abn, Liq Oxy, Control No. NAS9-150." A Beech Aircraft Corporation label is wrapped around the central tube. The port features a screw-on cap, retained by a green wire.