For proper operation, make sure that the units of measurement in the scene are in mm:
Customize - Units setup - System unit setup - mm
The carpet material is made using a Displacement map (make sure that Displacement is enabled in your scene settings).

4 sizes of carpet in the scene:
- 200*300 cm.
- 160*260 cm.
- 120*170 cm.
- 80*150 cm.

https://www.benuta.eu/fur-rug-dave-beige-60007456-21101.html?url_key=fur-rug-dave-beige-60007456-21101 

More carpets: http://3dsky.org/collection/shared/5321350