Mansfield Essence Drop-in with a 4" center Model 259-4-BISC is a Biscuit 20?x18?rectangular sink. This lavatory if you so choose can be used with a wall mounted faucet. The Mansfield Essence Drop-In Lavatory with a 4" center Model 259-4-BISC is made of a durable vitreous china material with a concealed front overflow. The Mansfield Essence Drop-in Lavatory with a 4" center Model 259-4-BISC 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.