What is the Subpod Grow Bed made out of? How long will it last? Dimensions?

What is the Subpod Grow Bed made out of? How long will it last? Dimensions?

The Subpod Grow Garden Bed is strong and stylish, made from high-quality steel with an anti-corrosion coating of aluminium and zinc for long life.  The expected life of this type of steel is at least 15 years.  It is 4 times stronger than galvanized steel.  

The bolts and screws are made from stainless steel which will also have a long life.  

Dimensions
120cm long x 90cm wide x 45cm high.