2.upper, middle and lower composite (double panel)
3.single face composite,
4.double-face composite
4.double-face composite
5.right-right butt structure (transition row, transition piece)
6.4-sided all-inclusive structure (copper-clad aluminum row)
7.can be customized without standard
6.4-sided all-inclusive structure (copper-clad aluminum row)
7.can be customized without standard