Munchkin Warhammer: Age Of Sigmar - Kill-O-Meter - Rules of Play says:

In the battle for the Mortal Realms, you need to know just how strong your opponents are . . . and how well you stack up against them. You'll have that information at your fingertips with the two-sided Munchkin Warhammer Age of Sigmar Kill-O-Meter. Turn the dials as your combat strength goes up or down so you always know how tough you really are . . . or flip it over and use it for the monsters! This set also comes with four new Munchkin Warhammer Age of Sigmar cards.