G'Day Fella's,

Gryphon, they appear to be EAW QD mount, that attaches onto a scope rail.
Note, there are No Scope Rings.
The top of that "Stack", claps onto a rail (Factory fitted), on the underside of the scope.

The rifle looks to be a Voere (?) M98, note what appears to be a tang safety?

Hope that helps

Doh!
Homer