I evaluated the device in terms of cleaning quality, but the build quality let us down, but this did not affect the main task. We purchased such a device after the birth of our third child. And he immediately became a good istant. The suction power is not very bad. It in not only dust, but also various small things, for example, self-tapping screws, nuts, cookies, candy wrappers, etc. like a big vacuum cleaner. He does his job very thoroughly. Don't go to the same place twice. Doesn't skip places. It swirls very beautifully around the legs of the table, . After watching his work at least once, you understand that you can safely entrust the dry cleaning of the floor to the robot and not think about it anymore. The whole design is very well thought out. But there is still something to complain about. Corner radii should be tripled. Then maneuverability in narrow places will improve. The noise level was not very comfortable. Strongly pestered rattling main brush. It was decided to try to fix it. A seal was glued into the bed of the brush bearing. Thus, the backlash of one brush shaft support was removed. But unfortunately the second support of the brush continues to play as the output shaft of the brush gearbox itself plays. This cannot be fixed without disembling the gearbox. But all exactly the overall noise was reduced to an acceptable level. After refinement, the sound level meter showed a peak of 72 decibels per meter from the robot.