CERTIFICATION EN250/2014 FOR COLD WATER THE T10-SEAL CHAMBER 1ST STAGE is environmentally sealed, protecting it against icing in cold water and against contamination from particulate matter in silty conditions. When paired with the Master second stage, which includes an internal heat exchanger, this regulator is an excellent choice for divers exploring the most extreme cold water environments. Very high performance regulator, same mechanics as the T10 Master but without the double stage regulator. Ideal for seasoned or professional divers who need extremely high performing equipment that is both simple and resistant, without any of the usual accessories that may get damaged.