3D Active Shutter Glasses are designed to view 3D images on Sharp DLP 3D-ready projectors with DLP Link Technology. Interactive glasses synchronize with the projector and 3D content to deliver a 3D viewing experience. Viewing distance is 2' per 100 ANSI lumen. For example, 3D glasses will synchronize from up to 50' back with a 2500 lumen projector. Glasses are battery powered and include a spare battery, a special tool to change the battery and wipes to keep the glasses clean. Battery life is 120 hours. Waterproof design allows the glasses to be cleaned in a sink or dishwasher.