Check out Magpul SL Hand Guard for MP5 Low-poly 3D model on CGTrader for $7. High-quality mesh by Akinaro: 2680 polys, 1322 vertices. PBR, Textured, UV Mapped.
OBJ (OBJ, filesize: 135 MB), FBX (Autodesk FBX, filesize: 135 MB), DAE (Collada, filesize: 44 MB), BLEND (Blender, filesize: 91.3 MB)