A stun grenade.
A stun grenade is a weapon designed to stun targets belonging to known humanoid species.
Earth Starfleet utilized this type of hand-held weapon during the 22nd century. These grenades are designed to have time-delay function.
In late-2152, a stun grenade with a three-second delay was used during the boarding-assault of a Suliban stealth-cruiser by the crew of the Enterprise. (ENT: "Shockwave, Part I")
The following year, while Enterprise was in the Delphic Expanse, it was raided by an Osaarian starship. During their raid, they made off with several items from weapons storage, including: three photonic torpedoes, a case of plasma rifles, two dozen stun grenades. (ENT: "Anomaly")
Archer ordered the MACOs to use a stun grenade to subdue their opposition during their raid of a Illyrian starship. (ENT: "Damage")