SL-MEE07 in the link that Zakiaz posted above.
It has one insulated container and a plastic top container that isn't meant for keeping things extra hot or cold. The bottom insulated container keeps chicken nuggets hot until after school if DS doesn't open it during school.
It's the smallest of the bento sets. If I get another, I think that I'll check out the slightly larger one with three stacking containers except for 2.
Here is the link to DS' model.
http://www.zojirushi.com/products/slmee
I never microwave the bowls. In fact, I line the bottom container with foil when he takes chicken nuggets or pizza bites or anything that is hot out of the oven. They sell replacement plastic interior containers too.
If I had to take my own lunch, I'd definitely go with the slightly larger model. Since DS takes his own juice packs, the bag that came with the set is too small. We use that as his snack bag on pizza day. Other days he takes the Zoji insulated jar in a larger lunch bag with his drinks and other snacks.
Worth every penny in my opinion. I think we got ours from Amazon over 3 years ago. It's still keeps everything nice and hot or cold.