I can't believe Revine got to sell this crap. Every detail is made of cheap materials. The Sponge Hepa filter is very thin. There's not even a seal after the orange screen. Thus, micro dust is distributed directly into the air through the sponge HEPA filter. But the description lies, it has a closed air duct. The sensors and the front wheel are even smaller than half of other vacuum robots. Not 5200 mAh, but 3200 mAh. No CE certification. Contacts to the store are roughly made. Please don't do that crap. Please do NOT let customers waste their time.