This grenade was produced in small numbers at the beginning of 1991, in the factory METALPLASTIKA in the town of Makarska in Croatia.
Like other croatian war-made grenades it is very simple in construction and was issued unpainted.
The body of the grenade was made using steel pipe which was shut on both ends with steel caps brazed on its ends.
On the upper side of the grenade has a drilled hole of 13 mm in diameter.
The explosive was filled through that hole and after that, the pyrotechnical slow-burning fuze with detonator No.8 was put in the grenade.
The space around fuze was shut with nylon which appeared not a good solution because damp could easily get into the grenade and make it useless.

Information thanks to Goran.

photos will follow