The model was originally created in 3Ds Max 2014, then textured and rendered using V-Ray3.6

Two stairs
Round stair
Spiral stair

Features:
-This model is accurately sized to match the real object.
- -All textures and materials are tailored and applied for high quality render results
- No extra plug-in are needed for this model.

Texture size

Concrete Color 2074 x 1208
Metal022 2K Color 2048 x 2048
Metal022 2K Roughness 2048 x 2048

Specifications:
-Model is included in 7 file formats.
3ds max 2014 file
3ds max 2013 file
3ds max 2012 file
3ds max 2011 file
3ds file
Obj file
Fbx file