1: Crystal shell: Personally, I think the crystal shell is useless. Because it is hard, it will still hurt the PSP when shaking, but the shell can protect it. Moreover, the handle of the crystal shell is poor, the thickness increases, the weight increases, and there is no comfortable feeling of holding it. 2. Silicone case: It feels a little better than a crystal case, but it would be tragic if you sweat a lot. PSP will be soaked in sweat all the year round, and the silicone shell is easy to accumulate dust. As for heat dissipation, don't worry. It doesn't matter if PSP is put in a waterproof bag and brought into a hot tub to play. 3. Sticker: It is born to abuse PSP. Except for looking good for a while and getting old for a while, those degummed and curled pictures will make you collapse, and removing the sticker is also a difficult technical job. 4. aluminum shell: it can be said that it is the most worthy case to protect PSP. Although it is not shock-proof, at least it does not have the disadvantages of silicone shell. Personal experience, using aluminum shell will not scratch PSP. 5.PSP has only one brand, Sony. PSP3000 and PSP2000 are portable, and PSP3000 is recommended.