Features: Schedule 80 UPVC ball check valves have a spherical ball inside the valve body which works as a check to allow flow in one direction and close off to prevent back-flow. Union check valve is made of SCH80 clear blue high quality upvc material. Premium material make the PVC union check valve durable and strong for long-term use. Better Rust and Corrosion Resistance when Compared with Steel Piping Systems Specifications: Material: PVC Color: clear Size: 3/4-inch Package includes: 2 X Clear PVC Union Spring Check Valve Notes: Manual measurement, please allow slight errors on size. The color may exist a slight difference due to different screen displays.