These are really cool hats! Use them for party events, nighttime illumination, sporting events, or just a regular hat during the day. There are no logos, so you are free to have your own theme embroidered if you wish. Glow Hats are battery and LED operated. They come with the first set installed and the batteries are replaceable. Glow hats feature 2 modes of operation activated by a small clicker inside the embroidering. They have a rapid flash, and steady on. These glow hats come in black fabric with the buyers choice of 7 different LED color combinations. The use of ultra fresh products,Average battery life is 72 hours.(battery replacement) These hats are size adjustable for a proper fit. Material: Cotton Specifications: 100% brand new and high quality. Made of cotton material,it is very comfortable to wear. LED lamp cap can be used for students to read, ideal for night fishing and camping, night repair very convenient. It can be used for medium-sized concerts, bars, discos, sports and other various dance. Package Included: 1 x LED Cap Notes: Due to the difference between different monitors, the pictures may not reflect the actual color of the item. Compare the detail sizes with yours, please allow 1-3cm error, due to manual measurement. Please leaving a message before you give the bad feedback, if the products have some problems. Thanks for your understandings.