The X-Shot Scope.
Currently supported versions:
Fury 4
Max Attack
This model contains 3 files:
1 Rail file for the Fury 4 (must be printed twice)
1 Rail file for the Max Attack (must be printed twice)
1 Scope file (same for both versions)
Needed:
1 Screw M4 - 20mm
1 Nut M4
The author hasn't provided the model origin yet.