The glasses don't have a battery; you connect them directly to a power bank using a USB-C cable, and they link via an app on your phone. You can adjust the lenses according to your vision. They also have speakers built into the same frame above the ears, with excellent sound quality. The glasses have a special system and browser that allows you to watch YouTube or any website. The glasses provide a screen size of 120 inches, and you can adjust the size. The glasses are new; I only used them three times. The reason for selling is that I have an eye problem where my eyes are sensitive to the glasses' light, and they didn't suit me.