Diverter Valve for Countertop Filter, A standard diverter valve that will give you a quick option to choose filtered and unfiltered water right on your faucet. The valve alternatively serves as the connector between your faucet and your filtration. It’s collar screws onto your kitchen faucets’ thread and will fit most countertop Filters that connect to a water faucet with a 1/4” or 3/8” single or double plastic tube water line.