Though disappointed my 7-year-old kitchen faucet started dripping, I was surprised & pleased the design included a widely used replaceable cartridge that installed from “above” the sink.  Delta sent one no-cost and a 15 minute install.  I didn’t have the torque wrench or large (1-5/16 in.) socket the directions suggested but got it done with tools on hand.  Works well so far.  Excellent customer support - thank you!