MonsterVision MVI SHUT 3D XMTR Max 3D IR to RF Transmitter for Shutter 3D Glasses 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 800+ hours of use in one charge