Slap Bracelet
Slap bracelets were all the rage in some schools in the early 1990s, and you may have seen them. They were cool, a little odd-looking, and you practically slapped them on your skin to put them on. You're smacking yourself, and that's badass. However, because they were harmful, they were swiftly removed from schools. It wasn't the slapping that was the issue; it was the bracelet itself.
The bracelets were made of a flat strip of metal coated in colorful fabric or paper, but after a few usage, the metal's edge could shred through the coverings. This would expose a sharp metal edge, similar to a playground shank. Schools were wise to step in and impose restraining orders on these wristbands.