The No. 2 grenade (also known as Hales pattern and Mexican pattern) is a percussion cap fragmentation and rifle grenade used by the United Kingdom during World War I.
To use the grenade, the detonator is inserted, the safety pin is pulled out, and the grenade is then thrown. Streamers on the grenade are designed to stabilize the grenade's flight so that it always lands head-first.
The No. 2 was created by Frederick Marten Hale in 1907. It was first used in the Mexican Revolution and was produced by the Cotton Power Company under contract from the Mexican government. France also purchased some as rifle grenades. The United States tested the No. 2 as a potential grenade, but it was not adopted.
When World War I broke out, it soon became obvious that the standard British grenade, the No. 1 grenade, could not be produced fast enough to meet with demand. To help meet supply, the British government purchased all of the No. 2 grena