The inner design is critical to successful contamination control technique. The inner gasket body forms an effective thermal transition between the ambient air and warm, humidiﬁed incubator atmosphere, minimizing condensation and eliminating moisture traps which can harbor contaminants.The inner door gasket is a dual durometer extrusion (two levels of softness) from closed-cell silicone to inhibit contamination. The gasket feather-edge allows the inner glass door to close gently against the chamber opening for a tight peripheral seal. The entire inner door gasket is removable for cleaning and/or replacement if required. Radiant heat from the outer door, apportioned by the microprocessor control as a function of the patented Direct Heat and Air Jacket, automatically warms the inner door glass in proportion to total heat demand and condensation control.