MonsterVision Max 3D Eyewear System with Active Sync - Glasses and Transmitterer Kit for Active 3D Fully compatible to work with all 3D-enabled televisions. World's first and only to work via radio frequency - no line of sight required. Transmitter can expand to thousands of pairs of MonsterVision glasses. Proprietary software embedded in the transmitter and reciever to prevent any loss of sync. Fully rechargeable with 60 hours of use in one charge.