Grass Valley 4300 Krystal Reference Manual v.3.1 - Manual (Page 33)

Krystal 4300 Reference 1-21
Physical Description
When suite 2 is controlling the channels the B video and key inputs on
those channels are selected. The operator in each suite must acquire the
correct Effect Manager to control that suite’s Switcher Aux bus selections.
This facility is also equipped with a 2 x 2 Combiner that allows the user to
combine both Krystal channels, and have the combined video and key
return to crosspoints on the switchers.