This grenade is the practice version of Yugoslavian fragmentation grenade M69.
It has the same body as
M52 practice (painted in white colour with 2 holes drilled on bottom part of it's body).
The fuze looks identical as the live fuze for M69, only the detonator is replaced by a black powder charge. This charge simulates detonation of the grenade. The grenade is fully painted in white colour(body ánd fuze cap).

Information thanks to Goran.