The F1 grenade is a defensive fragmentation grenade, designed to be thrown in cover and at range in close quarter situations as this grenade will fragment upon explosion, sending hundreds of hot shrapnel flying at different directions. The F1 has an even bigger damage output and radius than the RGD-5 so one should not be surprised if the grenade wounds the player at ranges where one is safe from an RGD-5 blast.
In Call of Pripyat grenades' shrapnel can seldom hit the player well outside its declared blast radius, resulting in severe bleeding or, on higher difficulties, instant death. In-game, it is best used against tougher but slower mutants (controllers, for example). When engaging other stalkers it is best used in open areas (since in game grenades can be thrown across a considerable distance) where its fragments can easily kill a whole group of densely packed enemies, in contrast to RGD-5s which work better in room clearing situations.
Hawaiian and Owl sell as well as buy this type of grenade.
The real world Russian F1 grenade is a copy of the World War One issue French F1 grenade, differing only in its fuse. It is the forerunner of many western style grenades, especially the American Mk.2 Defensive Grenade and British No.36 Mills Bomb. Although the grenade only has 60 grams of TNT compared to the RGD-5's 110 grams, the outer shell of the grenade is ribbed for extreme shrapnel dispersion, making this a very deadly weapon to infantry.
Initial supplies of the French F1 grenade were issued to the Tsarist Russian army during World War One. Large numbers were later captured from "White Russian" Tsarist forces during the Russian Civil War. It was made the standard grenade of the Soviet forces and is still manufactured and issued today.