Adopting German imported hardware (ROTO/Segenia) and multi cavity structure, with wind pressure resistance of 9 levels (> 5000Pa) and sound insulation of 42dB. The original UPVC profile is equipped with high-quality lining steel, which increases the strength by 300%. Multi channel sealing design, heat transfer coefficient K < 1.3 W/(m² · K), energy-saving exceeding the national standard by 40%. Through 200,000 opening and closing tests, it can withstand temperatures ranging from -50 °C to 80 °C and has no corrosion in coastal environments for 30 years. Can be configured with internal opening and internal tilting, with micro ventilation and rain protection for greater safety.