Especially with regard to screen protectors, there is a wide choice of materials and thickness. These screen protectors are often made of glass or plastic. The glass version is generally more robust. When you drop your smartphone, the glass screen protector absorbs the impact and cracks itself, instead of damaging the screen. Plastic protectors are also often available but are a bit more difficult to apply, because air bubbles can remain under the screen protector when it adheres to the screen of your smartphone.
Other accessories though, are nearly always made of some type of plastic due to the robustness of that specific material. In our capacity of wireless speakers supplier and smartphone chargers supplier we have supplied countless entrepreneurs and stores with such products.