Choose our reliable 19x20x4 HVAC filters for exceptional air filtration in your home or business. These filters, from premium brands, ensure your HVAC system operates at peak efficiency, providing clean and healthy air. Upgrade to our 19x20x4 filters for the best performance. These cartridges are designed for use with Honeywell air cleaner housings. 19x20x4 size is designed as a replacement for the Honeywell FC100A1003-209894.