Part of the PRW Anti-Twist Servo Mount System introduced on the 4.8 platform, this product is for only the 3 carbon servo mounting plates. Plates are notched for easy identification. 1 Notch = MKS/Sanwa/Exalt size, 2 = Futaba BLS671, 3 = Futaba S9650. Every common servo size comes right in the 4.8 kit, no modification needed!