Our Lead Glass Shields are used as a barrier to prevent X-Ray radiation while allowing a safe and clear view into the vacuum system. The shield is mounted to the atmosphere side of a standard CF type Zero-Length viewport using longer than standard bolts (bolts not supplied). The vacuum seal is made by the Zero Length Viewport.
Larson Electronic Glass offers "Lead Glass Shields" available in 5 standard sizes that mount on CF flanges from 1.33 inch to 8 inch diameter. Dimensions are in inches.