Crack on the knob end.

A baton (also known as a truncheon or nightstick) is a roughly cylindrical club made of wood, rubber, plastic, or metal. It is carried as a compliance tool and defensive weapon by law-enforcement officers, correctional staff, security guards and military personnel. A baton may be used in many ways as a weapon. It can be used defensively to block; offensively to strike, jab, or bludgeon; and it can aid in the application of armlocks. The usual striking or bludgeoning action is not produced by a simple and direct hit, as with an ordinary blunt object, but rather by bringing the arm down sharply while allowing the truncheon to pivot nearly freely forward and downward, so moving its tip much faster than its handle. Batons are also used for non-weapon purposes such as breaking windows to free individuals trapped in a vehicle or turning out a suspect's pockets during a search (as a precaution against sharp objects).