A hanger box — also called a hanger pack or fat pack — is a retail card product designed to hang on store pegs, typically containing more cards than a standard pack but fewer than a blaster box. They're the mid-tier retail option between single packs and full boxes.
Hanger boxes are popular because they offer more cards per purchase than a regular pack at a reasonable price bump. Some products include exclusive parallels or inserts that are only found in hanger box configurations, giving collectors a reason to grab them even if they're also buying blasters or hobby boxes.
If you're walking through Target or Walmart and want something with a little more volume than a single pack without committing to a full box, the hanger is your move.