The massive ATEM 4 M/E Constellation HD doubles the features of the 2 M/E model with 40 x 3G-SDI inputs, 24 x 3G-SDI outputs, 4 DVEs, 16 ATEM Advanced Keyers, 4 multiviews and 2 SuperSource for 12 x DVEs in total. ATEM Constellation HD switchers feature a compact rack mount design with a built in control panel. This allows operation of the switcher, critical during setup or for emergency use. Also included is a large LCD so you can see program output and change switcher settings via on screen menus. The compact design is perfect for portable live production, with the rear of the switcher including the connections for 3G-SDI inputs, 3G-SDI aux outputs, balanced audio and Ethernet for control. The top 4 M/E model even includes RS-422 for serial control and MADI digital audio connections. Even with all this power, ATEM Constellation is extremely quiet with its innovative high efficiency thermal system.