Compatibility lookup
- Air filter by size and MERV
- Refrigerator water filter by part number
- OEM part-number replacements
- Mini-split filter finder
- Hayward pool cartridge cross-reference
- Waterdrop RO replacements by system
- Sump and septic high-water alarms
Machine-readable data: filter-sizes.json, fridge-models.json, replacements.json.