Spiral staircase with landing, handrail, railings and floor slabs with grouped objects for easy editing. A perfect staircase for interiors of homes and offices. The tread and riser are in standard size 6 inch height. Floor to floor height in 10 feet. The railings are 2 feet 6 inches. Available in both SKP, STL and OBJ formats. I have used only 2 materials and everything is grouped well. A great interior stair for mini DIY projects.