... noise ,portable 3.self rechanging 4.pretect detector vacuum robot cleaner 2.Stair avoidance detector 3.Virtual wall detector 4.Wall ... and lightweight, comfortable and safe. 2. With automatic navigation and intelligence function, press the switch to automatically clean the room. 3 ... , the noise only 70 dB, far below the normal vacuum cleaner. 4. Ultra quiet vacuum box and strong adsorption ability, you ...