Structure: Connected extrusion structure with integrally formed expansion units.
Process: Side screw-driven partial expansion, eliminating the need for positioning and adjustment.
Function: Automatically level when screwing in screws; no misalignment even if only one side screw is installed first; screws are flush with the profile surface.
Application: Mid-to-high-end doors/windows, system windows, and scenarios requiring seamless miter joints and high stability.