Product Name: 1/4″ x 1/4″ O.D. tube L quick connector one way check valve set of 6Easy to Install: New generation Non-locking Clip technology offers an easy DIY installation without tools required, just push in to Connect.Material: Food-Grade POM Tubing, passed by US NSF CETIFICATIONUsing Temperature: 5℃ -45℃Burst Pressure ≥2.8MPaSuitable for all water filters, purifiers, reverse osmosis systems using 1/4″ water filter tubing fitting. Provide Doube Sealing for less possiblity of leakage. Note:the arrow indicates «passage», and the reverse direction indicates » check valve”