As the name suggests, each bag contains a mix of caramel popcorn and cheddar popcorn.
The sweet and savory combination is popular in the Chicago area and apparently originated from there some time ago (outside the Chicago area, it probably occurs more by happenstance when someone removes the divider from a holiday popcorn tin).
Smartfood Caramel & Cheddar Mix comes in a 7-oz bag that retails for around $3.99 (may vary).
Photo via Frito-Lay.