How to find your under-sink water filter system model number

Start with the mounted filter head or manifold

Open the cabinet and look above the cartridges. The system model is often printed on the filter head, mounting bracket, manifold, or a label on the back or side of the assembly. Use a phone flashlight and photograph the full installation before removing anything.

For reverse-osmosis systems, also check the membrane housing, storage tank label, and any control box. The faucet itself usually does not identify the complete system.

Record system and cartridge numbers separately

The system model identifies the complete filtration setup. A cartridge number identifies one replaceable stage. Both are useful, but they are not interchangeable. Copy every character, including dashes and suffixes.

• Brand and complete system model
• Number printed on each installed cartridge
• Number of filter stages or housings
• Rated membrane capacity for an RO system
• A wide photo showing tubing and tank layout

If no label is visible

Check the owner's manual, purchase email, installer invoice, or account used to register the system. Do not match a replacement by cartridge size or color alone; standard-looking housings can contain different media and use different schedules.

If the system and cartridge labels disagree, use the manufacturer's current replacement chart or contact its support team before ordering.