Lunch box?

I can't access the comments for my last post for some reason so I'm reposting!! (If you commented on my last post can you please comment again? Sorry!! And thanks!)

Hi mommies. My son is 13 months old and eats mainly table food but I always bring other options/snacks/pouches/water with us wherever we go just in case. They are currently in a gallon size ziploc in my diaper bag but I would love something more permanent. Suggestions for an insulated lunch/cooler bag? Preferably something flat so that I can slide it into my diaper bag? Thank you!!!!