The Soviet F-1 hand grenade (Russian: Фугасный > Fugasnyy 1, "Explosive, Type No.
It is also nicknamed Efka (Russian: Эфка) for the letter F.[3] It is similar to the American Mk 2 "pineapple grenade", which was also ultimately modeled on the French F-1.
There was a myth originating from an article written by Peter Kokalis [citation needed] for the Soldier of Fortune (magazine) that implied UZRGM fuse variants are available in versions with delays from zero (i.e., instantaneous, specifically for use in booby-traps) to 13 seconds.
It has a steel exterior that is notched to facilitate fragmentation upon detonation and to prevent hands from slipping.
While the F-1 is no longer regarded as a front-line weapon with the former Warsaw Pact countries, it still remain in widespread use specially with insurgent groups.
[6] Several countries produced copies of the F-1 grenade, including China (as the Type 1), Bulgaria, Czech Republic, Georgia, Poland, and Romania.