Humbler stun device
From Halopedia, the Halo wiki
The Electric Baton is a nonlethal weapon used by the UNSC Marines mostly for "motivating" others in a painful but relatively harmless way.
When the Spartan children first arrived at Reach in 2517, Electric Batons were used by Chief Petty Officer Mendez to "motivate" them at first, though they soon grew to cooperate with him, and the devices were not needed.
These devices are also used by police forces to subdue suspects, as noted by Aiden Maki.
