... dust treatment,via plywood ot metal.,do seal via treatment at out doorEnergy saving,low noise, steadylong lifeDigital programme control system ... through the door,,it will increase the speed at the beginning,at 4-6 circles /min speedSlow speed: when old man,children or ... entrance,when meet object pressed,the door will stop revolving at once to prevent hurting personAnti-collision sensor:installed inside ...