Iron Flask Food Jar, Sky, 13.5oz/400mlIron Flask Food Jar, Sky, 13. 5oz 400ml Iron Flask Food Jar, Sky, 13. 5oz 400ml Whether youre going on an outdoor adventure or simply taking your lunch to work, say hello to Iron Flasks Stainless Steel 400ml (13. 5 oz) Food Jar. With its double wall vacuum insulation and powder coated finish, the exterior stays sweat free while keeping your food cold for up to 9 hours and hot for up to 6 hoursso your yummy meal is always at the right temperature.