Feringer oven:
450 x 745 x H 855 mm
https://www.ozon.ru/product/pech-dlya-bani-mini-pf-layn-teleskopicheskiy-tonnel-990292371/?at=QktJLqD7zc19zDEEikQzA1Mi6LRB03HponnVwinowWyx 

Without Turbosmooth modifier:
Polys: 31,681
Verts: 33,518
With Turbosmooth iterations 1 modifier:
Poly: 254,520
Verts: 130,444

The Displacement map is used;
The Turbosmooth modifier with Isoline Display was applied to the required objects;
There is an FBX file (if necessary, apply the Turn To Poly modifier to the FBX file);
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.