2RU rack mount philips / BTS / Thomson / Grass valley machine interfacemodel MI3040 (Same as grass valley MI3040B)used usually with Jupiter plus control systemsto look after the tally(Eg with the VM3000B etc usuall installed with also)Usually used for tally control and other controls for routers like venus, jupiters and othersalso use with vision mixers like xten, DD35 series like DD30, dd20, xten etc, and many others etc to give the mixer tally in and out etc