Disclaimer
The Letter Box Shop only uses 445m2 / N4 Marine Grade Stainless Steel for its face Panels and Plaques.
http://www.australwright.com.au/News/June07/445M2%20bro.pdf
In extreme cases a brown discoloration known as TEA Staining may occur on the surface of the stainless steel. Tea staining does not effect the structural integrity of the product.
If this does occur the please contact The Letter Box Shop for a product recommendations to clean the Tea staining

