Radial Engineering R8001100 ProDI Passive Direct BoxCapture Pristine Audio Signals with Confidence The Radial ProDI is a high quality passive direct box designed for stage and studio use. With its custom wound Radial transformer and rugged construction, the ProDI delivers exceptional audio clarity and eliminates noisy ground loops, ensuring a clean and professional sound. Key Features: Custom Radial Transformer: Provides superior signal handling. High Input Impedance: Reduces loading and distortion.