Mag-grenades were a type of grenade.
Mag-grenades were used by Jedi Master Relin Druur around 5000 BBY. Around this time, at the outbreak of the Great Hyperspace War, he used mag-grenades effectively during his infiltration of Sith Lord Saes Rrogon's dreadnaught, Harbinger. Druur utilized mag-grenades in an attempt to destroy the ship's hyperdrive, although this was only partially successful; the Harbinger still attempted to jump into hyperspace, although it failed to completely enter its hyperlane and accidentally traveled over 5,000 years through time to the year 41 ABY.
During the Galactic Civil War, Rabid Mynocks leader Quayce used a dud mag-grenade during a race with the leader of the Spiders, Dean Lado. The grenade distracted Lado enough to cause him to be caught in a massive repulsor minefield explosion.