How to choose UPVC front doors and frames
2.When the UPVC front doors is closed, there is no gap between the fan and the frame. The upvc front doors are connected as one body without screw connection. The sliding doors should be freely slid, the sound is soft, and no dust falls off.
3.The upvc frames and the fan have steel lining. The glass is installed flat and firm and does not directly contact the profile. If it is double-layer glass, there should be no dust and water vapor in the interlayer, and the switch components are tight and flexible.
4. upvc front doors and frames must be professionally processed in the factory workshop, not on-site production