1.For 16 hours continuous operation 2. Low-speed design, quieter operation, longer life INSTRUCTION 1. Low-speed design, quieter operation, longer life.2. Reed valve design, efficient.3. Filter paper air filter core of imported production, filtration and silencing effect, durable.4. Solenoid imported brands.5. Piston Ring of Japan RIKEN, durable, non-oil.6. Ventilator-channel maze structure to ...