I accidentally purchased this item. I opened the package, but it is unused. This is an ABS resin Aqua Home replacement cartridge, compatible with various water purifiers, with a working pressure of 0.05MPa and a diameter of approximately 4.5cm. - Product Name: Aqua Home Replacement Cartridge C-KMD-50-Z - Material: ABS resin - Size: Approximately 4.5cm in diameter - Working Pressure: 0.05MPa - Compatible Models: For various water purifiers - Replacement Period: 1 year (may vary depending on usage) Thank you for looking.