Our knitted beanie is warm and comfortable, with images of colorful, glowing Christmas bulbs. How to activate: (Step 1) Inside the seam of the hat there is a hidden switch. Turn the switch to the on position. (Step 2): Press the on/off button to activate the lights. Batteries included and installed. THE BEST PARTY FAVOR | We makes an incredible party favor. Great for family celebrations, holiday birthdays, secret Santas soires, office and ugly sweater parties. It makes a great holiday hat stuffers for boys, girls & adults. Wear it while snowboarding, walking the dog, ice skating--or making love after the heater breaks down in the dead of winter. One size fits all. Led Light-up Knitted Ugly Sweater Holiday Xmas Christmas Knitted Wool Christmas Hat-merry Christmas