Our 3D shutter glasses are developed in-house,so there is Simple circuit structure ... required. To start the auto detect process, turn on your glasses firstly.Step 2. Light (3) will blink until auto ... seconds, battery level is low.Charging the BatteryTo charge the glasses, plug the USB cable in computer or other USB charging ... piece per bag, 100 pieces per carton Hot Rechargeable Universal 3D Glasses