This finnish defensive grenade has a cast body. It's fuze was a percussion type which had to be struck to a hard surface to ignite the delay. Two safeties had to be removed, first the brass cap (after pulling the ring), and then the small clip around it's stikerpin rod.
The top and base of the grenade are connected by a wire that keeps them together.
Both top and base have 6 notches each over which the wire is placed.