You need Substance plugin to edit materials.

Materials were created in Substance Designer 5.6.

Each material has up to 30 tweakable parameters, which depends on material complexity: base material (color, roughness, wear level, normal intensity, etc.), dirt (color, opacity, dirt level, etc.), paint (color, pattern dimensions, pattern disorder, roughness, corrosion, etc.), plastic (color, roughness, roughness disorder, normal, etc.), rust (spreading level, smoothness, normal, etc.) and emissive color.

Any material can be instantiated to create multiple variations for each mesh.