ShineMate Backing Plate DA Heavy Duty (5" and 6")ShineMate Heavy Duty Backing Plate A super durable backing plate without going full aluminum. This is ShineMate's answer to increasing power transfer from pad to panel without going full aluminum. The heavy duty power plate uses the same designs from the ShineMate Dust Devil plates with great multi hole ventilation, an air gap between the hollow top and bottom housing with increased stiffness and no flex. You can expect a 3 8% increase in power