https://www.emmanueljonckers.com/reflexion-12/ 

Dimensions: 120 x 200 x 40Hsm
Polygons: 47752

* If using OBJ apply MeshSmoth with 2-3 iterations.
* Who works 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 lower than 3.1 then the BRDF field will be empty. Choose Blinn Phong or Ward – which is preferable for you