This defensive grenade is also used with an attachment to launch it from a rifle.

Total length : 110mm
Diameter : 50mm
Weight : 320gram
Filling : 66gram HEXOGEN/TNT
Fuze delay : 4 - 5 seconds

Photos and information © Raúl Alberto González and Manuel.

The drawing above on the right is one version of two.
On the two photos below you can see the two versions and their fuze mechanism differences.

The photo on the right shows a box of fuzes for the FMK 2. These fuzes were called `FMK-3 Modification 0`.

Photos © Cory :

Rifle grenade version :