Just interested if anybody else has had problems using these (Killflash) and whether its just the TENEBREX or also is a problem with the USO honeycomb filters/shades. When I bought my Horus-H2 it had one on - and I've always just assumed that the slightly fuzzy image was the HAKKO scope (as teh later ones have had quality issues). But following a thread on the SWFA forum - removed it and the difference is pretty stunning. I guess it might be a must if the genuine reason is to KILL FLASH - but as a sunshade imo its not worth the effort. What is even more astounding is that asking any non-shooting optics expert - they all agree that it's a diffraction grating so must affect the light paths.