The rubber-coated mounting magnets with internal(female) threaded rubber bushing (shorted as internal thread rubber-coated mounting magnets) offer magnetic bases for waterproof magnetic ceiling hooks and rustproof holding magnets for outdoor use. All the internal thread rubber-coated mounting magnets are made with N35 neodymium material, which produces the strongest strength. For different applications, you can screw different threaded hooks and lifting rings into the internal thread post.