This grenade was produced from 1993 in Serbia.
It has the same construction and dimensions as
LRB M3 but this grenade is filled with chemical agent CN instead of CS.
It was called LANSIRNA RUČNA BOMBA which means "HAND GRENADE FOR LAUNCHING", as it was shot from the metal cup threaded at the M70 Yugoslavian automatic rifle barrel.
That system of firing was made before 1991 also for
Croatian engineers in 1991 made metal cup for firing the
RB100 grenade by copying that yugoslavian pre-war made cup for LRB M3 and later LRB M3/93.

LRB M3/93 is a smoke type grenade with CN chemical agent mixed with smoke filler.
The fuze of the grenade is not detonating type, the igniter fires a black powder pellet in the grenade.
The flame of the black powder ignites smoke filling mixed with CN chemical agent.
The grenade body has four holes on its upper part for emission of the irritant CN gas after it's activation.
Body of the grenade is made of aluminium.

photo will follow