1. The product shall be assembled and installed easily without gap and deformation;2. Both flanges shall be at same level. Check product on a flat surface. 3. The flange cover shall be easy to snap in, not too loose or tight. The flange cover can still be rotated but cannot be pulled off easily after installation on the wall.4. A minimum of 1.5" space between the wall and grip.5. The welding joints should be even with holes & false welding.6. The flange installation holes shall be welded to the right position per drawing.