These are pretty good for kids to send hot food to school or to take out when babies are starting solids. I think also good for people who are on the road for work. Can use on ski trips to have hot lunch without paying crazy ski resort food prices. It helps to fill with boiling water first, then drain and dry before adding your food to preheat it.
I also use to keep things cool like berries for my kid to snack on.
Not quite as cheap as the Kmart equivalent ($9 350ml / $12 500ml) but I think a bit more compact in terms of space efficiency in a bag and some may prefer the look of this one.
Not to be confused with this one at Woolworths that looks the same except in Dark Blue which is showing as $26 https://www.woolworths.com.au/shop/productdetails/872343 . It also worth noting that the one on sale is showing as ‘out of stock’ but using the stock checker there seems to be plenty available in most stores.
+1 for the write up, thanks OP