Pack of 2 elbow check valves, 1/8" male thread convert to 1/4" OD water filter PE pipe Built-in one-way check valve core, effectively prevent water backflow in RO reverse osmosis pipeline Push-in quick connect design, one-step installation without any auxiliary tools Food-grade safe plastic, non-toxic, harmless for household drinking water purification Compact elbow shape, ideal for narrow space pipeline turning layout of water machines, Manufacturer: FonFou