Pros:

• Sustainable and cost-effective ecologically designed lantern activated by salt water! It is a really amazing product.
  -It is a sustainable and cost-effective ecological lantern that uses salt water or ocean water to activate the fuel cell and generate electricity
  +It generates power enough to light up your lantern.

Cons:

• Saltwater accessibility might be a problem here. Mountainous areas will definitely find it hard to acquire saltwater. Aside from that, the toxic elements incorporated in saltwater may damage this lamp in the long run. I highly agree with @smaeunabs idea.