Spiral Staircase v2 Architectural Stairs 360 — professional 3D model by modernarchstudio (CGTrader). Price: $22.
STL (Stereolithography, filesize: 70 MB), OBJ (OBJ, filesize: 186 MB), 3DM (Rhinoceros 3D, filesize: 10.9 MB), DWG (AutoCAD, filesize: 36.9 MB), 3DS (3D Studio, filesize: 35.5 MB)