The Open Skid Layout: The engine and alternator are bolted directly onto a welded steel channel frame. It has no outer steel box or soundproof foam.Vibration Isolation: The engine is mounted on heavy-duty rubber anti-vibration pads to keep the open frame from walking or shaking during operation.Weight & Size: Open units are roughly 20% to 30% lighter and much smaller than silent canopy models. This makes them easier to transport in truck beds or fit into tight equipment rooms.