$5 Kastle Picatinny Riser Low-poly 3D model by Akinaro. Available on CGTrader with 4324 polys and 2164 vertices. Check it out on CGHub.
BLEND (Blender, filesize: 79.9 MB), BLEND (Blender, filesize: 79.9 MB), OBJ (OBJ, filesize: 79.9 MB), FBX (Autodesk FBX, filesize: 79.8 MB), GLTF (glTF, filesize: 41.7 MB), DAE (Collada, filesize: 80.2 MB)