SainSonic SSZ-200DLW 3D Active Rechargeable Shutter Glasses for DLP-Link Projector, White Fashion Design: Beautiful color, portable and comfortable. Light weight for long time wearing. Upgrade function: Press the power button one time to turn on/off glasses. Press the power button two time to change the left lens and right lens. Green consumption: Recharge with micro USB cable 3 hours recharging provides 50 hours operation. Automatic POWER OFF function: When 3D projector is powered off or not synchronized with 3D signal,3D glasses will be AUTO powered off after 30 seconds. Rubberized nose piece & ear tips make you more comfortable to wear with.