Self Defense Ring- 100% legal

I was looking for non-lethal self-defense apparatus has to use in case something happens. Well I was at this show and I asked the police officer about this ring I'm like you know is it legal? He looked at it, me, and smiled and kindly said yes it's just a ring know you're fine. It's large probably about a 9. Has crosses and emblems, adorn on all sides and looks to be golden color.