1. Excellent heat and water insulation 2. Sound insulation 3. Good air tightness 4. Environmentally-friendly Specification: 1. Material: -Aluminium Alloy - UPVC Materials (Model: 60, 70, 80, Chameber: 3, 4, 5, 6; ) (Reinforcement Steel Wall Thickness: 1.4, 2.0, 2.5 mm) 2. Design: As order. 3. Size: Customized; drawing draft for customer information. 4. Glass: Single glass, Double glass, Clear ...