... and spacer air-proof,water -proof,sound insulation,anti-corrosion,wind pressure,easy maintain Aluminum windowsSystem-aluminum sliding windows ... grain,other treatment can choose:anodic oxidation,cataphoresis,powder coating and fluorocarbon coatingGlass-5mm, 6mm, 5+6A+5 ... customers` sizesFeatures-air-proof,water -proof,sound insulation,anti-corrosion,wind pressure,easy maintain Package-Foam ,hard paper, ...