Two pieces of metal scope mount rings. Made of CNC machined aluminium, so it's guaranteed they are more precise than common die-cast rings.
Interesting is the way of mounting of the scope. Common rings have a separated upper part which is fitted by 2 allen screws. Here you have only one screw which adjust left and right half in one moment. Not only it's faster, but it also can't affect the axis of the scope.
Suitable for common scopes with 25mm tube diameter. Rings can be mounted on a standart RIS rail. One of these rings has a small level, so you see if the scope is mounted in the right way and also if you hold your weapon right, because you will negatively affect the accuracy if you hold it slanted.