1.economic type 2.mop function 3.two strong side brush 4.lower noise 5.adjustbale anti-drop sensor ultra- ... function3,manual charging4,low noise(less than 50db)5,with ultraviolet sterilization and fragrance6,four cleaning routes: random, spiral ... , along the wall, polygonal spiral7,cleaning automatically8,with obstacle, cliff and bumper sensitive sensor9,fashionable appearance, nice ...