I need help to find the best blade to buy for self harm.

[OnnanokoNiNaritai]

Okay so, i still live whit my mother and i cant ship a blade to my house and have no way to buy anything online whitout she finding it out yet.
I need a type of blade that i can buy PERSONALLY.
Im portuguease if that helps

 

[lamy's sacred sleep]

 

[OnnanokoNiNaritai]

Woopsie mb