This is one of the hypersonic grid fins that can be found on the Falcon 9 SpaceX Rocket, specifically the Block 5 version. It is used to manipulate the direction of the rockets lift during reentry.
I modelled this grid fin in Blender and Textured it in Substance Painter, to be used as part of a bigger project.
SpaceX Falcon 9 - Block 5 Grid Fin