Classic U1 · Special Stainless Steel · Treatment Process· Self-adaptive Anti-shake Spring· Misoperation Prevention Supported Performance Features of Tilt&Turn · Invisible System, The Pioneer of Axial Rotation Structure· National Invention Patent for Track Structure· Fully Replaces the Slide Groove Structure· Smoother Opening and Longer-lasting Use · 0-180° Opening and Closing (Manual Switching)· Suitable for Sash Width of 350-850mm· Suitable for Sash Height of 450-1400mm· Load-bearing Capacity up to 60kg