$2 Picatinny Shell Holder for Shotgun Shells Low-poly 3D model by usafguy21. Available on CGTrader. Check it out on CGHub.
OBJ (OBJ, filesize: 3.97 MB), 3DS (3D Studio, filesize: 2.02 MB), FBX (Autodesk FBX, filesize: 1.87 MB), MAX (Autodesk 3ds Max, filesize: 7.05 MB), GLTF (glTF, filesize: 18.6 MB)