RGO and RGN Specnaz grenade

The RGN and RGO grenades were developed under Project BAZALT ("Basalt") during the Soviet–Afghan War to supplement the RGD-5. When in combat in the mountains Soviet troops found their grenades were less effective. The steep terrain often caused grenades to accidentally bounce or roll back towards the thrower's position and cause friendly casualties. The long fuse time allowed the enemy forces to get under cover – or even throw or knock the grenade back if they were lucky.

The RGO's time delay fuze prevents friendly casualties if it impacts too soon or will air-burst over an enemy under cover if it hadn't impacted. The impact fuze detonates when it hits any terrain – even sand, snow, or water.