AIR DIFFUSER ,METAL CUSHION BOX ,BOX 1.could increase air direction from one way to three way 2.Connect with flexible duct AIR DIFFUSER ... ,METAL CUSHION BOX ,BOXcould increase air direction from one way to two ... lowe priceCorners will be sticked with aluminium foil to avoid air leakSize as required We, with 500 people, several distributions ...