... by CCS. RHZK series rhzk is a self-open air ventilator, widely used in fire control, chemical industry, shipbuilding, petroleum ... metallurgy, warehouses, laboratories, factories and mines, and other departments, for firefighters, rescue workers, and mine workers in smoke, vapour, oxygen ... , meet the GA124 rhzk. Marine respirator with CCS for type approval and inspection. self-open air ventilator