5PCS/Lot Brass Hex Lock Thin Nuts Plumbing Pipe Fitting M10 M12 1/8" 1/4" 3/8" 1/2" 3/4" 1" BSP Female Threaded Hexagonal
https://www.vogueparade.com/shopping/EN/200282142/1/33039551632/5pcslot-brass-hex-lock-thin-nuts-plumbing-pipe-fitting-m10-m12-18-14-38-12-34-1-bsp-female-threaded-hexagonal//