1Pcs Check valve plastic backflow core DN10,14,15,16,20,OV15,20,25,32mm prevents backflow Water meter fittings valve plugged in
https://www.vogueparade.com/shopping/EN/200282142/1/33051397510/1pcs-check-valve-plastic-backflow-core-dn1014151620ov15202532mm-prevents-backflow-water-meter-fittings-valve-plugged-in//