It's a professional restoration of the maple flooring surface, including a replacement of noise steps. We started sanding with sandpaper size 60, then 80. Then, we sanded next with an orbital machine with sandpaper size 60 and 80. We cut part of the step to install the new noise.
We also made a gap-filling, then sanded with a buffing machine with 100 grit sandpaper. Finally, we finished with three coats of clear matt lacquer.
The job took 8 hours.