Profile: Nevtek is the manufacturer of the ASI 400 air stream incubator. The incubator provides critical maintenance of physiologic temperatures on unenclosed microscope stages and can be used with an instrumentation where control above ambient is required. Our ASI 400 remote incubator provides a non-cyclical, electronically controlled air stream, assuring temperature stability and complete access to both the specimen and equipment. Temperature control of better than ±0.2°C is achieved by means of a proportional controller. A quick response thermo-sensor monitors the temperature of the high-velocity air stream. Delicate optical equipment is further protected from deleterious temperature changes by means of an electronic fail-safe device built into the ASI 400 incubator. There is no need to enclose the microscope. The problem of differential heating of specimen and equipment as occurs with infrared stage heaters does not exist. The temperature of the specimen is stabilized rapidly. The filtered, high velocity air stream inhibits interference from room air currents and prevents dust contamination.