When they brought the vacuum cleaner, the first thing I thought: is it a toy? The vacuum cleaner is really small, but powerful, more powerful than I had a regular, non-vertical one before. Vacuums well, including carpets. It heats up a little during operation, I do not know if this is normal. Also, when I turned it on, I heard some extraneous sound, it whistles, and only when I move the vacuum cleaner. Therefore, my assumption is that the whistle is from the wheels of the main nozzle. In general, I am satisfied with the vacuum cleaner, it does its job perfectly. I really hope it lasts a long time