This is a digital download:
 
Spiral Stair Set v4 270 degree 20 treads.  The model is exported in various formats. Model is organized by layers so you can apply your own materials.
 
This is perfect for Architects, Students, Engineers who want a completed model for their library, or project.  
 
3DM - Rhino
3DS
DWG
OBJ
STL
 
Ask me about other formats.  If you have questions or issues, send me a message.