A sink is designed which can be converted into one, two or more separate basins. The sink has at least one rib protruding up along its inner surface. A removable dividing wall is provided with a plate portion and an elastic flange extending around the bottom and sides of the plate. Two detents extend from opposite sides of the sink at the ends of the rib. The detents engage the flange and deform it against the rib tightly enough to create a waterproof seal and separate basins. Drains are provided on either side of the dividing wall.
