This durable copper check valve is designed for piston-type direct- compressors and -free pumps, ensuring reliable performance and durability. Its non-return functionality prevents backflow, maintaining optimal air pressure and efficiency. The threaded design allows for easy installation and secure connection to various pneumatic systems. Features -Color:Golden -Material:Copper -Size:4.00X3.80X3.50cm/1.57X1.49X1.38in -Copper check valve design: crafted with durable copper, this check valve effectively prevents gas backflow, ensuring stable and reliable operation of your air compressor system - -free piston structure: the -free eliminates the need for regular maintenance, making it ideal for applications requiring clean air, such as medical and food processing industries -Direct : drive mechanism minimizes energy loss, enhancing operational efficiency for quick inflation tasks in homes, auto repair shops, or small factory -Compact : its small and lightweight design makes it easy to carry and store, perfect for mobile operations or work spaces with room -Quiet operation technology: advanced noise reduction technology ensures a quieter working environment, ideal for noise-sensitive areas like offices or residential spaces Package list: 2 compressor check valves