Columbia series is a broken bridge window and gauze fan integrated outward opening system window. The window and gauze fan integrated a simple style design and the frame and the inner fan flush, full of aesthetic feeling, three-dimensional sense is stronger. At the same time, the gauze net is connected to the profile, which greatly enhances the impact resistance; ensuring the anti-mosquito effect and not affecting the indoor lighting. The heat insulation strip is designed on the same vertical line to achieve excellent waterproof sealing, soundproofing, and heat insulation performance.