... smoothly 4.do not occupy room space sliding window grill design Product description:1. Profile:aluminium alloy, 6063-T5 2. Wall thickness: 1 ... rust, rot, warp, or need constant finish maintenance. The aluminum frame will last for years and years, even as it endures ... , wind, and snowstorms. or need constant finish maintenance. The aluminum frame will last for years and years, even as it endures ...