The RGO hand grenade (Ruchnaya granata Oboronitel'naya) is a defensive Russian fragmentation hand grenade. It consists of a double layered steel pre-fragmentated body. It is very similar to the single layered offensive/defensive RGN Hand Grenade. It uses the UDZS dual action fuze, which has both impact and time delay functions. The impact fuze activates after a pyrotechnic delay of 1 to 1.8 seconds. If the impact fuze has not triggered the grenade after 3.2 to 4.2 seconds, a second pyrotechnic delay triggers the grenade. The fragments produced by the grenade generate a lethal radius of between 6 meters and 20 meters, with the safety radius being 100 meters. The grenade is still in production in Russia and Ukraine and is still in service with a number of countries.