This is the Russian F1(Ф1), a High-Explosive-Fragmentation (HE-Frag), defensive, striker-release (SR), hand-grenade, nicknamed the Limonka (lemon-like), used as an Anti-Personnel (AP) hand-grenade and also used as part of a booby-trap (BTP), it has been copied in many countries including Romanian and the Czech-Republic (RG-F1).
It is based on the French F1 hand-grenade being introduced during World War II and subsequently redesigned post-war. Fuze variants are available which give a Delay (DLY) between zero (instantaneous) and 13 seconds, specifically for use in a BTP. The F1 hand-grenades are shipped with shipping plugs installed, the fuzes are inserted once in the field.
The hand-grenade has to be deployed from a defensive position to avoid harm. It has a steel exterior that is notched to facilitate HE-Frag upon detonation and to prevent slipping from the user’s hands. The distance the hand-grenade can be thrown is estimated at 30 to 45m.