eYourlife2012 Mens Winter 5 lED Lights Lighted Night Fishing Knitt Beanie Hat Cap Roll-up Brim 100% Acrylic Material: Acrylic One size fits most. 5 LED lights with 2 CR2032 lithium batteries. Lights built into the rolled brim. The batteries can work for 12 hours continually, the light will be dimming after 12 hours, light will go out after 24 hours.. You can exchange the batteries after it goes out.