Tupperware 3-Piece FridgeSmart Set From Tupperware Containers control air supply of refrigerated fruits and vegetables Produce "breathes" and needs varying amounts of air to stay fresh Two vents in each container open and shut according to contents' needs Raised grids on containers' bottoms elevate food out of its own moisture Set comprises three containers: 19-1/2-cup, 7-cup, 4-1/2-cup