The CF Viewport Flange is designed for vacuum systems that require visual observation through a sealed flange-mounted window. The catalog lists a pressure range of 1 × 10⁻⁸ mbar to ambient pressure and notes that custom dimensions are available upon request. It is available in Stainless Steel 304 / 1.4301 and Stainless Steel 316L / 1.4404, using Borosilicate or Quartz glass and FKM / Viton O-ring material, with standard sizes from DN40 to DN160.