WPC (Wood Plastic Composite) wall cladding or decking panels.
These are hollow, rectangular slats with interlocking profiles, typically used for:
Exterior and interior wall cladding
Ceilings or decorative facades
Partitioning or siding applications
They come in different wood-like colors (brown, reddish-brown, and grey in the image) and have a textured finish to resemble natural wood while being more durable and low-maintenance.