1.The door frame's guiding groove is designed separately, which enhances the door's anti-theft performance and prevents unauthorized opening.2.The profile design features a large section and the internal fan material is integrated for equal pressure and decompression between the outer frame and inner fan. This improves the airtightness and torque resistance of the door, and can withstand drop hammer impacts. This ensures that the doors and windows do not crack easily in cold regions.3.The door frame is designed with a two-chamber system, providing strong rigidity and an independent drainage cavity for smooth water drainage under any circumstances.4.The sash corners are reinforced with stainless steel at a precise 45-degree angle for added strength and durability.