Chairs Ray Soft collection from the company Brunner with the base Four Feet Extensions, slider. In three versions: low, medium and high back. The base is presented in three colors: aluminum, black and white.

Links to the manufacturer's website / store:
Low back: https://www.brunner-group.com/en-DE/products/details/ray-soft_9615/A/ 
Middle back: https://www.brunner-group.com/en-DE/products/details/ray-soft_9625/A/ 
High back: https://www.brunner-group.com/en-DE/products/details/ray-soft_9635/A/ 

On the seat applied modifier TurboSmooth. For all models, a sweep.