This is an Align DS450M Digital Cyclic HV Servo (HSD45001T). It features a full aluminum alloy case construction for heat dissipation. It supports high voltage input (DC 6.0-8.4V). Stall torque is 3.0kg.cm at 6.0V and 4.0kg.cm at 8.4V. Motion speed is 0.06sec/60° at 6.0V and 0.05sec/60° at 8.4V. It is suitable for T-Rex 250/450/470 series RC helicopters.