You can buy it on aliexpress: https://s.click.aliexpress.com/e/_opl...
The detector is designed to search for hidden electrical wiring, metal, wood, pipes in the walls. Detection depth up to 12cm under ideal conditions.
Search for studs behind drywall, search for a base behind a wooden wall. Search for pipes in the walls.

To save your time, I registered timecodes:
0:00 Equipment.
3:00 Controls, what is on the display, modes
6:39 Search for wires in the wall, calibration
12:40 Search for metals in the wall
18:30 Search for wood and metal, partitions behind the wall
21:49 Result