... noise ,portable 3.self rechanging 4.pretect detector vacuum robot cleaner 2.Stair avoidance detector 3.Virtual wall detector 4.Wall ... 5 L / s 1. Circular dispatch styling, avant-garde fine, compact and lightweight, comfortable and safe. 2. With automatic navigation and ... , the noise only 70 dB, far below the normal vacuum cleaner. 4. Ultra quiet vacuum box and strong adsorption ability, you ...