After 8 years I carried out an internal cleaning of my active KRK that were placed on it. The person who carried out this cleaning told me that she had rarely seen so much dust inside, We have, we examine with a microscope, we realized that it was the foam of this support that can little by little, had entered my speakers, as well as on some of my peripherals that have always been close to this support. So I cleaned my peripherals (sound card, HUB, etc.) by opening them, and indeed, I found this foam dust inside all my equipment, placed close to this support.
The price, interesting and effective, but be careful I don't know why this foam is degraded?
And indeed I realized that simply by rubbing the foam it decomposed into crumbs, then into dust.