40mm Grenade

[ron3350]

I need the correct name for this possibly Russian 40mm Rifle Grenade.
It looks like a riot-control or bursting type with 6 body slots in the steel.
The fuze and adaptor are aluminium. Liner is orange plastic. Length is 102mm.
The base of the fuze is not threaded. Any information is welcome.

 

[sgdbdr]

It's a flash grenade named GSZ-40 (ГСЗ-40)