Stainless Steel:

Stainless steel is a low maintenance material that is suitable for both indoor and outdoor use.

There are two grades of stainless. These are 304 (standard grade material) or 316 (marine use grade. Suitable for coastal areas). 

The  linish #4 is on one side only and a satin (plain finish ) on the back

The stainless steel also comes with a one sided protective coating to protect it during installation.