Why does Stihl MS291 crankcase seal have fiber layer? 9638 003 1581

[MEKinOL]

I’m putting an MS291 back together. The flywheel side seal I got from Stihl has a fiber-like outer covering. The fiber is flexible. The center of the fiber has a smaller diameter than the crankshaft and the rubber sealing lip. The fiber will deform and will fit over the shaft when slid on. The seal I removed does not have the fiber layer. Should I keep the fiber or cut it off? If left in place, what is its purpose. The stihl part number is 9638 003 1581. Tia advance.

 

[cookies]

Its a extra preventative to keep debris out of the seal