I think, in this case, the image of the Lunch Man says it all.
Yes, it's a lunch box, shaped like a 1980s Walkman, so you get to keep your sandwiches in one piece whilst looking cool in an gadget geek kinda way.
It's made of plastic, it's sized at 18 x 14 x 5.5cm and the Lunch Man is available online for just £6.