Used to select a range of channels in numerical order.
1 Thru 5 @ 50
Selects channels 1 to 5 (1, 2, 3, 4 and 5) and sets their levels to 50.
Thru can also be used in place of the last channel number to automatically select the last channel
1 Thru Thru @ 50
Selects all channels and sets their levels to 50.
Using Thru and several other modifiers you can make a more complex range of channels