Safety light for antenna

I love gas station giveaways. I almost missed this at a yard sale. They had it in the box and not displayed. They only had a few things so I went back over everything again and saw the box. They had a blank side up. Pulled it out and saw advertising from near where I grew up and it was mine.

You would slide this over your car antenna if you broke down. Turn it on and once it warms up it blinks. I put a battery in it and to my complete surprise it still worked.