Filbur FC-0122 4CH-19 PSG13.5P4 Spa/Pool Filter Cartridge is a replacement spa and pool filter cartridge from Filbur Manufacturing, built for systems that use this specific Filbur cartridge style. The listed cross-reference details include 4CH-19 PSG13.5P4, which can help match the cartridge to the filter currently in service. It is intended to help restore steady filtration by trapping debris, body oils, and suspended particles as water moves through the filter housing. When an old cartridge becomes worn, stained, collapsed, or difficult to clean, replacing it can help improve circulation and support cleaner, clearer water.This cartridge is a practical maintenance item for spas, hot tubs, and pool applications where the correct size and end-cap style are required. Always compare the part number, cartridge length, outside diameter, inside diameter, and end configuration with the filter being replaced. Regular rinsing and periodic replacement help reduce strain on the pump, maintain water flow, and keep the sanitizer working more efficiently. Replacement Filbur Manufacturing spa/pool filter cartridge for compatible filtration systems Use part number and cross-reference markings to verify fit before ordering Helps capture dirt, debris, oils, and fine particles during normal circulation Supports improved water clarity and more consistent filter performance Ideal for routine maintenance when the existing cartridge is worn or hard to clean