ATEM 4 M/E Constellation HDThe massive 4 M E model 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. Introducing ATEM Constellation HD, the world's most powerful HD live production switchers! These incredibly powerful HD switchers are available in 3 great models, including a 1 M E model with 10 inputs, a 2 M E model with 20 inputs and a massive 4 M E model