I use these windscreens primarily as a pop filter (what they are meant for, of course), but also for assigning mics by colour to a specific member of the band recording in my studio and, last but not least, for hygienic reasons, preventing a singers "produce" to creep into the mic's capsule(...) Because of the latter, I also wash them after a session. After the first wash, however, the colours faded significantly, turning the originally bright primary colours into their pastel versions - except for the black one, which remained unaltered. I think this one is made of black foam, while I think the other four are made of white foam which has been dyed. They still fit snugly to my mics, though, and are not very vulnerable when slipping them on and off. Of course, they still serve as good pop filters too, but I wonder what they will look like after a next wash - hopefully the colours remain recognizable enough for colour assignment... And consider these are much cheaper than the original black windscreens supplied by Shure themselves.