“The new grenade, called the M111, becomes the Army’s choice for urban combat, when troops must clear indoor areas to take and hold territory…
It’s the first new grenade introduced for US forces since 1968
…The use of shock waves, or blast overpressure (BOP), kills or disables enemies with the force of the explosion, vaporizing the weapon’s plastic outer shell.
Troops outside an enclosed area can throw the new grenade into that area, and enemies cannot take cover behind interior walls, furniture or appliances that shrapnel may not be able pierce, the military said.”
https://www.yahoo.com/news/articles/us-army-first-grenade-since-080054444.html