A set of 130 repeating textures with 16-bit bump (roughness) and normal maps.
The creators have even shared a suggested shading network to help you get started:
We are using the pxrRoundCube to make the texture tileable and then distributing this placement node across Multiple PxrMultiTexture nodes (diffuse, normal and roughness), which will give us the most options for seamlessly tiling our textures.