Royalty Free License 
Original kitchen model downloaded from from https://www.turbosquid.com/3d-models/free-obj-model/1064415
Converted using Bullet/Extras/obj2sdf

This kitchen was originally using the royalty free license https://blog.turbosquid.com/royalty-free-license/

However, in personal email the author gave permission to use it for any purpose with Bullet:
You can use it freely with Bullet, without restrictions.
Author contact: info@fabrika3b.com