The hardware of door window that sells on the market at present has home bred and import cent.  

Domestic hardware lock the two generally have a point, and import hardware usually have 3 three locks, its principle is when the door lock, lock, lock button firmly together, together with hinges or sliding, common strong sealing pressure, make the sealing rubber strip elastic deformation, thus providing enough for doors and windows sealed performance.  

Accordingly, the hardware fittings with poor quality, also can make the sealing performance of aluminum materials for window greatly.