From the website:
Knit cap with LED lights keeps you warm and lights your way in the dark.
Comfy black acrylic pullover hat features 5 super-bright LED bulbs stitched into the brim.
Provides 7 hours of forward directional lighting for navigating through the dark or working in low-light situations.
Ideal for joggers, bikers, hikers, and outdoorsmen.
One size fits most.
Has on/off switch.