The Teeth: The jaws have sharp, serrated teeth angled in one direction. These are designed to "bite" into the metal as you apply pressure.
The Swing: There is intentional "play" or wiggle room in the top hook jaw. This allows the wrench to bind onto the pipe when you pull the handle, creating a powerful grip that won't slip.
Adjustment: You turn the knurled metal nut to move the top jaw up or down to fit the diameter of your pipe.
Located at Mozart Bet Building First Floor Shop F25