This is the OmniSwivel Shut off Valve 1 OD 9/16-18 Male to Female Features: 9/16"-18 Male to 9/16"-18 Female Insert 1" OD, convex design with hard knurrel suited for cold water use. Arrow indicates flow ON direction Delrin Sleeve Solid Brass Construction Shut-off / Isolation Valve: Turn ON or OFF flow.Made with 02 compatible material."