Blessing card security window casement type (Patent No. 201420178681.6), the main batch used in residential, villas, hotels, etc. real estate construction projects. Compared with ordinary flat open building with windows, its technical advantages are mainly reflected in:? ?? A, via a link from the mass of the structure to increase the positioning block (also play a supporting role), the connecting rod to withstand the weight of the driven fan capacity enhancement can be achieved double hollow glass or installing insulating glass, improving the entire window insulation, sound insulation properties. Meanwhile, the positioning block can also play a role in limiting and guiding open. Not easy to make the window open after being closed the wind, while increasing the maximum angle limit lever to limit the window open. Institutions in the closed, has a self-locking force, so that fans can turn to drive through flat open pan fan is turned on, open less forceful. In short links through improvements achieved in the use of mass transportation structure is more reasonable, more upscale effect. ?? 2, the border between the fan and the additional slots through profile design, so that when the hinge is installed, eliminating the process of opening in the profile, the hinge makes installation and future maintenance of the entire open fan easier! ?? 3, sash in the closed state of the formation of two seals, significantly improves the water-tightness, air tightness and sound insulation performance of the entire window. ?? 4, through the use of profiles open fan handle the design and installation of the way, making the window type upscale look and durable, strong lock.