Solved rough and dull shape problem with innovative new f-s system, manual pop-up handle available (1 4 locking cams available), automatic pop-up handle available (2 locking cams available with sf-77nd), solid pvc track rail, one-touch stopper, epdm gasket integrated gb.
Widen opening due to 3 track rail(12 ?23), capable of applying on high-rise building with enhanced structural strength stemming from hetero-profile welding system, manual pop-up handle(14 locking cams available) and automatic 2 locking cams available, trendy projected handle.