Check out Realistic Military Backpacks Low-poly 3D model on CGTrader for $15. High-quality mesh by marsbeket: 7889 polys, 4136 vertices. Textured, UV Mapped.
OBJ (OBJ, filesize: 423 KB), FBX (Autodesk FBX, filesize: 863 KB), GLTF (glTF, filesize: 120 MB), DAE (Collada, filesize: 98.5 MB), BLEND (Blender, filesize: 988 KB)