Culligan US-4 Installation and Use
The Culligan US-4 attaches to any standard kitchen faucet aerator thread in under 5 minutes: remove the existing aerator (pliers + cloth to protect finish), select the adapter from the included set that matches your aerator thread (internal or external, standard or metric), thread the Culligan US-4 adapter onto the faucet, and snap the filter housing onto the adapter. Culligan includes adapters for approximately 90% of US residential faucet aerator configurations. The US-4 has a lever to switch between filtered and unfiltered water flow -- use unfiltered for dishes and filling pots; use filtered for drinking and cooking water.