Pulse Grenades are a new type of weapon introduced in Resident Evil: Revelations. It is a hand-held explosive device that stuns all enemies within the blast radius. It can also be thrown underwater.
"Delivers a powerful high frequency pulse, causing temporary paralysis."
Once thrown, the Pulse Grenade explodes with a high frequency blast, stunning all nearby enemies. Enemies that have a stun animation, like the Hunter and the Ooze, can then be hit with a melee attack.
This weapon is of special note since it is the first weapon in the Resident Evil series that can be used underwater. When used underwater, it stuns enemies just like it would when used on land, however there is no melee attack that the player can do when underwater. Nevertheless, the Pulse Grenade is a vital tool when swimming through the flooded areas of the ships since enemies like the Sea Creepers and Globsters are much faster swimmers than the player.