Aluminum Folding windows 1. The standard glass trough not only improves the performance of the entire window, but also improves the flexible opening andanti-theft functions. 2. Reasonable drainage design can effectively prevent water seepage. 3. 45° angle reinforcement, stainless steel material makes it stronger. 4. Double track, frame and glass panel are designed with unique drainage holes. 5. The hollow glass filled with argon can reduce the U value and increase the heat insulation effect to achieve the purpose ofenergy saving.