· Two Door Type This model is for 2 person s working face to face for large capacity working and sequence working. · Economical Model Space save model, can set many units in the same small space. · Utility Device 110V/220~240V Concent, Gas Cock, Vacuum Cock, Hour Meter. · High Efficiency Filter Keeping clean space with High Efficiency Main Filter(0.3 , 99.99%) and Exhaust-Filter. · Vertical Air Flow Type Wind is come from the top to the bottom.