The disc is thick, feels very solid in your hands and is available in 58mm, 62mm, 67mm, 72mm, 77mm and 82mm filter sizes. On one side, you'll notice a micro prism-like pattern that gathers light from a 180 degree angle of view. When flipped over, you see a smooth, opaque white acrylic, similar in color and feel to white Plexiglas. The two circular discs are enveloped by a black, high-grade aluminum that has a perfect finish and texture. You'll also notice a string that attaches from the aluminum filter casing to the supplied neck strap. I found this combination to be smartly designed and convenient for me when I was shooting in scenes that had changing light conditions. I tend to wear shirts with pockets on them, so rather than allow the filter to dangle from my neck, it was easy to put the disc in my pocket and the strap around my neck, keeping it ready at a moment's notice. If having the disc in your pocket isn't your cup of tea, ExpoDisc also provides a well made holder that has a loop in the back for belts. My only complaint with the holder is that it's got a velvet lining. While this looks and feels great, the disc fits into the holder very tightly and rubs off the velvet, which attaches onto the ExpoDisc. I had to consistently wipe down the disc after storing the filter in the case because there was enough of this black residue on the disc that I felt it could have the potential of throwing off the color reading when I white balanced. Still, this is a minor inconvenience and I expect that the more I use the case, the less this will be an issue. If I were grading the build materials, the ExpoDisc would receive a solid "A."