There are some fibers stuffing a LNB's opening waveguide. The LNB brand is EchoStar (the black one), probably around 10GHz. There are no labels with the exact model of this EchoStar. It was scrapped from a retired satellite dish of about 1.5 meters diameter.
Image 1: The LNB with fibers stuffed in the round Aluminium waveguide is the black one, brand EchoStar. Near it, there is another white LNB from another smaller satellite dish.
Image 2: Black case and waveguide removed, the fibers are stuffing the cavity on the right, near the 2 screws. The square entry cavity is 2cm x 1.5cm (about 0.8x0.6 inch)
Image 3: Just to see what's inside the LNB
Image 4: A closer look inside, with sunlight
Image 5: The other side of the inside. Please note there are some white fibers on the inside of the Aluminium flange.
Image 6: Fibers on flange, under microscope, magnification x10
Image 7: Fibers on flange, under microscope, magnification x30
Image 8: Fibers stuffed in the square entry cavity. Microscope x10.
Image 9: Fibers stuffed in the square entry cavity. Microscope x30.
What material is that? Could it be Asbestos fibers?