Warner Instruments’ Bold Line CO2/O2 Gas Controllers from Okolab digitally control O2 and CO2 concentration and can be fully integrated with Bold Line temperature controllers. The gas controllers are suited for hypoxia and hyperoxia experiments. Two versions are available—CO2: 0 to 10% and O2: 1 to 18%; and CO2: 0 to 20% and O2: 1 to 95%. Gas flow rates are digitally controlled. A long-life zirconium oxide sensor precisely measures the O2 concentration, and a non-dispersive InfraRed dual wavelength detector sets the CO2 concentration. Operation is via an easy-to-use touchscreen interface, OKO-Touch. An optional Smart Box data logger and web server allow operation via any web-enabled device. The system may also be operated via a PC using OKO-Control 2.0 software or Nis Elements software.