1) According to customer's size.
2) DIY
3) Proteced from UV.
4) SGS Test report of ASTM Standard

Features:
1) For DIY assemble, without lead
2) Corrosion proof
3) Age resistant
4) Maintenance free
5) Long usable life
6) Post height (mm): 1,000, 1,200, 1,500, 1,800
7) Standard center distance between posts (mm): 2,500mm
8) Installation method of post: embedded or foundation bolted
9) Colors: white
10) Suitable for household yards, residential properties, parks, roads,
pergolas (flower tresses), and other products including picnic tables
and garden chairs.

SGS Test report of ASTM Standard