Mansfield Brentwood UnderMount Model 234-BONE is a Bone 21?x15?rectangular sink with. Is mounted to a counter top for easy quick installation The Mansfield Brentwood UnderMount Lavatory Model 234--BONE is made of a durable vitreous china material with a front overflow. The Mansfield Brentwood UnderMount Lavatory Model 234-BONE comes with the limited lifetime Mansfield warranty. Mansfield is an American company that?s been in business since 1929, and has been one of the top producers in design, and quality for the past 40 years. They are the largest domestic producer of sanitary ware, and strive to ensure you get the best products available.