... ~ +60°COptimal Viewing Distance12m-80mDisplay Color1,070,000,000Gray Scale16384gradesBrightness Control256gradeFrame Frequency60HZRefresh Speed>300HZPower Supply220V/50HZMTBF≥ ... Even no back frame, the base can support the whole display if only the display's weight is 4m ... professional LED manufactures in China .we offer the LED display applied in Bank ,stock ,transportations , hospitals, stadium ...