Powered by advanced air-cooled 4-stroke direct injection diesel engines. Large silent muffler&balancer shaft inside and high effcient noise-proof materials,vibration-reducing structure combine to form a silent machine. Emergency low oil shutdown stops the engine immediately when the lube oil drops below a safe level, preventing costly engine seizure. Large fuel tank ensures hours of continuous running. No fuse circuit breaker provides overload protection and condenser voltage regulator guarantees stable voltage output. Durable 4-wheel rolling stucture for portability and operating indoors or outdoors.