A lavatory faucet stems replacement part is a component that replaces a worn-out or damaged stem in a lavatory faucet. A stem is a metal part that connects the handle to the valve seat inside the faucet body. It has a washer or a rubber seal at the end that prevents water from leaking when the faucet is turned off. A stem may need to be replaced if it is corroded, cracked, stripped, or broken. Lavatory faucet stems replacement parts may vary in size, shape, and function depending on the type and model of your faucet. You can find lavatory faucet stem replacement parts at hardware stores, home improvement stores, plumbing supply stores, or online retailers. You can also contact your faucet manufacturer for replacement parts or warranty service.