... ,powder coating 4,OEM welcomed aluminum extruded profile for speaker shell ContentsSpecificationsThickness0.8-4.0mm or as client's demandsMaterialsAlloy: 3003 ... , Non–corrosive, Firm and durable, Resistance aging, Long service lifePackingPlastic film inside,plastic buble bag,/brown paper,/outside rolled by craft paper ... .172≤0.1≤0.1 aluminum extruded profile for speaker shell