The blend file consists of all 12 models on their own layer, and 1 layer with a simple lighting setup. All models come with these textures (2k resolution): Diffuse, Specular, Roughness, Ambient Occlusion, Normal. The materials are set up using the Principled shader (Cycles).
Note: The Specular map also contains roughness information within the Alpha channel, which will save you some memory. Ofcourse you could also just use the rougness texture included.