Buy from Amazon : br br Signstek GX-30 Rechargeable 3D Active Shutter Glasses for Acer ViewSonic BenQ Vivitek Optoma br br Fashion Design Beautiful color portable and comfortable Light weight for long time wearing br Green consumption Recharge with micro USB cable 3 hours recharging provides 50 hours operation br Automatic POWER POWER OFF function When 3D projector is powered off or not synchronized with 3D signal3D glasses will be AUTO powered off after 30 seconds br Perfect match the DLP-Link Projector with the logo of 3D DLP Ready br Using new generation 144Hz technology ahead of other 120Hz products level