Similar in basic design to an electric cattle prod. It has a metal end split into two parts electrically insulated from each other. At the other end of the shaft are a handle and a switch. Both electrodes must touch the subject.
The stun baton is extremely effective in close quarters melee combat as (if there is a battery inserted) it can knock players unconscious in one or two hits.
It was probably part of the Chernarus Police Department equipment before the outbreak.