... surface ,mechanical polishedFeatures: 1. Alloy of aluminum extrusions : 6063 or 6061 2. Polish extrusions color : Silver, champagne, bronze, golden , ... polishing Thirdly ,anodized with color .4. specialty of aluminum extrusions : surface very soomth without any track ,brighter than ... common anodised .5.produce standard of aluminum extrusions : GB/T 5237-2004. ISO 9001:2000 certificated 7 ...