V-Ray 3.6 and Corona 5 versions

Preview rendered in Corona 5

System unit in mm

For Corona Render: It's recommended to use version 1.5 or higher, as the material glossiness is adjusted for PBR

For those using V-Ray versions earlier than 3.1: In the materials, the BRDF section should be set to Microfaset GTR (GGX). If your version is older than 3.1, the BRDF field will be empty. Select Blinn, Phong, or Ward

https://www.chehoma.com/en/lighting/chandeliers-hanging-lamps/40271-black-hanging-lamp-spirale/