light-weight, portable, easy-to-use, multi-fuctional pocket loudspeaker Features of Waistband amplifier:This pocketphone is small and light, to be kept in one's pocket, and its sound can cover an area of 50meters.It can be widely used in many outdoor environment, such as school, colleges, kindergartens, meeting rooms, classrooms. And it can also meet the needs of salesmen, street venders, ...