Nordfab® QF® O-Ring is designed to seal raw edges within from ducting lines. It's mostly used to replace the Black O-Rings provided standard with the Adjustable Sleeve.
When ordering replacements, choose Black Buna-N for standard applications. Choose Red Silicone for high temperatures.
It's available with 3" - 24" diameters in either Black Buna with a temperature rating of -40° to 250° or Red Silicone with a temperature rating of -75° to 450°.