The ETH-TALLY Link Tally System is a great add-on for your live video-production. The tally light have two LEDs - one facing the camera operator and the big one facing the presenter. The operator LED have both program and preview tally while the presenter LED is just for program. The two switches on the tally light enables the operator to turn on/off the main LED and to dim the operator LED. The Tally Box System handles up to 8 tally lights, connecting either directly via the box, or by daisy chain running from tally light to tally light.