Plastic chair with ergonomic backrest, stackable, for offices and commercial spaces.

The model is made according to the manufacturer's dimensions and photos:
https://www.bizchair.com/products/ergonomic-heavy-duty-flex-comfort-classroom-stack-chair-sf-ch003 

There are 2 copies of the model in the scene, each with its own configured material assigned.

Dimensions:
height 76.6 cm
width 43.5 cm
depth 55.1 cm

The model in the scene has a Turbosmooth modifier assigned to it in Render Iterations=2 mode, which is applied only during rendering.
In the obj file the model is saved using Turbosmooth.

All objects have normal names.
All materials have convenient names.

Weight of the model without Turbosmooth:
25,306 polygons
25,691 vertices

Pivot Point is aligned to the center of the model.

Those who work in V-Ray version lower than 3.1, be careful, in the materials in the BRDF section there is Microfaset GTR (GGX), if your version is older than 3.1, then the BRDF field will be empty. Select Blinn, Phong or Ward - what is preferable for you.

For Corona render, it is recommended to install version no lower than 1.5, since the glossiness of materials is configured taking into account PBR.