Feature 1、Installed at the outlet of the water pump to prevent water backflow and damaging the pump impeller. 2、Wide range of uses, suitable for swimming pools, hot spring sauna pools, baths. 3、Clean and visible chamber design, making it easier to see if any debris is trapped in it. 4、The installation is simple and does not require complicated operations, save time and effort. 5、Made of ABS and PVC material, resistant, rugged and durable. Item Type: Check Valve Material: ABS+PVC Weight: Approx. 727g/25.6oz Nominal Diameter of Interface: Approx. 2in/60.2mm Purpose: Install at the outlet of the water pump to prevent water from flowing back and damaging the pump impeller Features: High-quality material, transparent and visible, anti- and durable, simple installation Installation and use instructions: 1. Determine whether the diameter of the pipe to be installed is consistent with the installation diameter of the valve. The nominal diameter of the valve is: 2 inches 2. Before the valve is used, a manual operation test should be performed to observe whether the sealing baffle of the valve will rebound to the original position to determine whether the valve is damaged during transportation 3. Before installing the valve, check: A. Whether the water pump on the pipeline used is in the closed state: B. Whether there is debris in the valve cavity, and keep the inner cavity of the door clean: C. The flow direction marked on the valve must be consistent with the flow direction of the pipeline liquid. 4. Before installation, clean the oil stains or other debris on the installation nozzle and inside the valve installation port. Package List 1 x 2in Check Valve Note 1. When connecting the valve nozzle with the pipe nozzle, please use special PVC glue.2. Please allow 0‑2cm error due to manual measurement. Thanks for your understanding. 3. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.