This air check valve is an OEM product from Aqua Exclusive™ which is designed for use in the air system of the Green Line Bio Filter. It ensures that no water can flow into your air pump when you turn off the system or if it fails. Over time the material may wear out and begin to crack eventually requiring a replacement. This item is sold individually and is made of high quality polypropylene (PPH) and durable rubber. Note, do not use a wrench or pliers when installing, hand tight is sufficient.
If you have any questions about replacing a the air check valve or another filter part, please contact our support team. They are 24/7 available to help you.