The listing, 2 LED Cap Visor Lights has ended.
My husband used these in his shop, when he worked outside on lawnmowers and whenever he needed more light. He was losing his sight. One has a button to press to make it come on and it uses 2 CR2032 batteries (not included). The other has a switch on the back to make it work and it can also flash, just press again. It also uses 2 CR2032 batteries (not included). I did test them both and they work fine. They slip onto the underside of a caps brim. That's why I showed the ad for them. They cost $14.99 each. These were new, just among his stuff.