oh, now i see. This is actually a different sort of pathetic insecurity that ends up being adjacent to self defense laws and weapons control restrictions.

Dunno how much of this you already know so if it gets splainey, please forgive it -

there's a whole class of things people carry because they're now afraid to go anywhere without some manner of self defense weapon. They feel naked and exposed unless they can strap up but some places won't let them. And of those weapons there are a subset that are designed to get around restrictions on carrying weapons around. most of those are designed to look like something with a peaceful purpose.

for example, if you are stopped by the cops and searched and they find a pocket knife, that could be bad. pbut if they find a pocket knife with an emergency glass breaker on the hilt, ah, you could have a peaceful reason to have pocketed it and taken it.

if you get in a road rage fight and you pull out a bowie knife from under a seat, there will be questions of premeditated violence. But with something like this doohickey there's room for doubt that you had it in the car for some other reason and just grabbed it when you thought you were in danger.

It's all this grey area thinking applied to the insecurity of young men... some of whom are worried about being hassled by cops, which is unfortunately a little easier to understand than when the college kids with disposable income buy the same thing 'just because'.

You will see things like 'emergency seatbelt cutters' marketed like this. If you look at them carefully, they're meant to be something you can clutch in your fist like brass knuckles or a kubotan. The intention is self defense in places where their preferred weapons would be prohibited. Of course some buy them without ever knowing.

Extreme measures.

the two on the left would be problematic here in UK. The right hand two (which are also advertised just as normal ruler) would be less so, depending how they were carried - they do have legit uses such as where a thinner ruler would bend and make the measurements inaccurate by a few mm - although maybe more suitable for the workshop or in a toolbox in the back of your car than in the door card (what the old bill here are concerned about is someone getting in a road rage incident and picking up an easy to hand weapon on impulse)

I know from personal experience that metal rules _can_ be sharp, without any sharpening, and those ‘rulers’ picture sure seem to have a _point_, be longer than three inches, and not fold.

That they are sold as ‘defense’ rulers not something like ‘rugged’ would seem to undermine most ‘it's for work’ arguments, like the intent here is clearly to be a weapon?

most-interesting-man-meme.jpg
"I don't always stab people. But when I do, I want to know how deep it went."

I mean... I am passionate about the metric system.

I carry something that is very obviously a club in my car. It's a miniature bat, and I absolutely can't carry that around with me on the street. After some cursory searching, I'm questioning whether having it in my car is even legal in North Carolina.

There is similar rules-skirting with "high power narrow beam flashlights" that are very obviously actually dangerously bright laser pointers.

I've never bought a pair of brass knuckles in my life, but I have bought a few paperweights that looked remarkably similar in form and were made of brass.
I wonder if that's what's happening here?

I am guessing that this is a way to try to get around rules about concealed weapons.

(When I was training in kendo; we had to be careful to not violate those rules when carrying blunt training blades in gym bags.)

Never belittle the physics that has sprung from males in pickup trucks in the woods. If they need defense rulers to dress a moose, give 'em. Who knows what quantum hyperspace they'll do?

In Hi Skool, science teacher explained math of pulleys, blocks-and-tackle, etc. She asked JimmaJo how that might be useful. He said, "I guess if you're in the woods and your truck got stuck in mud, you could wrap a rope around a tree and use it to pull the truck out." True story!

The edge is blunt and it's rather thick.