... , air can be well-distributed PLASTIC 4-WAY PLENUM aluminium blade Characteristics1,Suitable for eco-cooler for vertical air supply, could discharge the ... The rim of Plenum is made of galvanized sheet material, with mould stamping forming, it’s size precision and intensity ... is aluminium extrusion molding, S-line structure, with it’s good properties for guide the wind, blade can manual adjustment, ...