This modular rack and tray system maximizes storage for petri dishes and cell culture flasks in incubators, cold rooms or on the bench. Perforated trays facilitate gas flow and slide without disturbing neighboring units. The stable construction even allows settling of cells. The system accommodates either one 14"" x 14"" tray or two 7"" x 14"" trays on each of the four available tiers. Up to five racks can be interlocked for 20 levels of storage, in just over one square foot. All elements are made of autoclavable stainless steel. Two racks are pictured in the photo.