This C-02 Honeycomb Grid from Godox is designed specifically for use with the RFT standard 7" Bowens mount reflector. It helps tighten the beam angle for a narrower light spread, as well as control spill light that can interfere with the background. Honeycomb grids are often deployed on a back light or kicker, where they serve to highlight a subject and give a pleasant contour to their face.
The C-02 Honeycomb Grid is specifically made to fit the Godox RFT 7" Reflector and may not fit other products.