2 Pcs Window Breaker Portable Mini Car Window Breaker Escape Tool Mini Glass Breaker for Land or Underwater Emergency Life-Saving self defence weapons uk legal

I was thinking Kubotan size, which is rough 6 inches of solid aluminium. They look nice, but as a self defence keychain this would be limited.I completely respect they are not marketed as as self defence tool, but if that is what you were thinking, this is not what you are looking for.