"Single-leaf double-channel" structure, the opening and closing of the sash is more stable
·New anti-falling device, safe and reliable, no fear of typhoon
·Multi-channel sealing design, sealing, dustproof, sound insulation effect is remarkable
Built-in strong diamond mesh, taking into account ventilation, protection, and anti-mosquito
·Supporting parts are perfectly matched, 100% independent research and development, own patent