Installation: 1. Clean and dry both sides of the pipe before use to firmly fix the valve. 2. Check the flow direction of the valve to make sure it is installed on the correct side. 3. Carefully connect the air pump check valve to the hose and connect it completely. Tip: If the valve restricts airflow in both directions, insert something into the hole on the intake side to push the valve down. The valve then allows the air to escape. flow in the right direction. 10pcs air pump valve for aquarium
