Optional O2 gas regulator designed for precise oxygen control in laboratory cell culture environments, compatible with CO2 incubators ST 45 and ST 180. This regulator enables stable and accurate oxygen delivery when connected to an external gas supply, supporting controlled atmospheric conditions required for sensitive biological experiments. The device helps maintain consistent O2 levels within the incubator chamber, improving reproducibility and reliability of cell growth studies. Engineered for laboratory use, it offers durable construction, secure gas connections, and reliable pressure regulation for safe operation. Ideal for research facilities, biotechnology laboratories, and clinical laboratories requiring optional oxygen control with CO2 incubation systems.