For Corona render, it is recommended to install a version of at least 1.5, since the glossiness of materials is configured considering PBR.
In the archive you will find: 3Dmax18 file, FBX and OBJ files.
There are 8 models inside: 4 models for 4 posts and 4 for 3 posts.There are 4 colors for each model: squirrel grey, sand yellow, orange, green.Renders was made with TurboSmooth 3 iterations that you will find inside and you can use it with more or less iterations.
https://www.vinciguerrashop.com/it/panche/17295-573250-panchina-dna-out-4-posti-true.html#/17845-scegli_la_finitura_true-ral_8012_red_brown
https://www.vinciguerrashop.com/it/panche/17292-573184-panchina-dna-out-3-posti-true.html#/17837-scegli_la_finitura_true-ral_7000_squirrel_grey