124ND Sliding Windows and Sliding Doors have widen opening due to 3 track rail (1/2 to 2/3), Capable of applying on High-rise building with enhanced structural strength stemming from hetero-profile welding system, Manual pop-up handle (1~4 locking cams available) and automatic 2 locking cams available, Trendy projected handle Widen opening due to 3 track rail(1/2 to 2/3)Capable of applying on High-rise building with enhanced structural strength stemming from hetero-profile welding system Manual pop-up handle (1~4 locking cams available) and automatic 2 locking cams available Trendy projected handle