These metal wall hooks for hanging are made of quality SUS304 stainless steel and perfectly designed, thus they are very sturdy and super practical. You can use them as small metal hooks self adhesive key hooks, stick on picture hooks for walls, stick on door hooks adhesive and so on. They are indeed ideal home storage hooks for small item organization at home and help to make our storage life much easier.The max load of these extra strong adhesive hooks is up to 3KG for long use and this is the conservative figure, in fact when they are properly applied on a smooth, clean and dry surface, the max load may increase to 5KG. They are small hooks self adhesive, thus they can be used even on uneven surface. But just be aware that different types of surface may affect the max load of these stick on hooks heavy duty adhesive hooks.