These are the Quixel dDo materials converted for use in Blender. If you don't have dDo they won't mean much. (If you don't, go get it... [http://quixel.se/ddo/](http://quixel.se/ddo/).They) ) .They are used to assign the proper spec and material details for dDo. (Just like color maps in Substance Designer). Bake AO first, with a default blender material. Once you have the AO, start adding the dDo materials. (if you assign them before AO baking, the AO will be tinted, which is undesirable). To use the dDo materials in Blender successfully, you assign them like any other material. Then before you bake "Textures"(not "fulll render") go to color management and set Device Display to "none" and color space to linear. This will ensure the Hex color values are correct in the exported bitmap. dDo will like your pretty little color maps and do crazy things with them. See the "dDo Widget" I post so you can play with in dDo. Thanks for the motivation Wiktor(dDo marketing and artist extrodinare)