A riot protection helmet is a type of helmet designed for law enforcement and military use to protect its wearer's head, face and eyes from handheld melee weapons, and thrown projectiles such as bricks, as may be met in riot control. Many modern riot squad helmets are reinforced with materials that will protect the wearer from dangerous substances such as acids or industrial chemicals. The riot protection helmets are usually made to be able to easily fit a Gas mask, especially when tear gas is being used.