... : Mill, Silver / Black / Red Anodized, Powder Coated, brushing, sand blasting, Painting, Polishing, etc.4. Price: Based on the processing charge. 5 ... . Length: Different finish, different length, the longest length is 7m for mill finish, and also based on the weight per meter ... that your design would be keep confidential. Aluminum extrusion Aluminium frame for solar panels