The Forma 3956 CO2 incubator is an excellent choice for large volume cell culture. Comes with 3 shelves & recorder. Chamber capacity is 24 cubic ft. Temperature range is 30 TO 60C. CH/P controller for automatic CO2 from 0 TO 20%, settable to within 0.1%. 2 humidity ranges: medium from 82 TO 87% RH and high from 91 TO 96% RH. Indicator lights display the RH selected. Heated glass door minimizes condensation. The unit can also be used as a regular incubator without connecting CO2