This pack is pretty straightforward:

-One Rigged Skeleton in FBX Format

-Skeleton and Skull Variations (all UVed) in FBX Format

-Six Substance Painter Bone Smart Materials

-Original Substance Painter File 

*FBX files work in any 3D App

*For the Smart Materials and Substance Painter files please use SP version 9.0 or higher (latest version is always better)

https://www.artstation.com/todryan